Please, can you provide more information about the filesystem? It would be nice to have a dump from the partition, 

  # dd if=/dev/sda3 of=vfat.img bs=1M count=40
  # gzip vfat.img

Note, that I can't reproduce the problem with a filesystem created by mkfs.vfat.

Created attachment 368265 [details]
dd if=/dev/sda3 of=vfat.img bs=1M count=40

Don't remember what I used to create /dev/sda3. Perhaps WinFLP. But Centos 5.4 reads it correctly

#blkid 
/dev/mapper/VolGroup00-LogVol01: TYPE="swap" 
/dev/mapper/VolGroup00-LogVol00: UUID="6e8cfa96-38b4-4bef-aef6-50b1635f206e" TYPE="ext2" 
/dev/sda3: UUID="48F6-4212" TYPE="vfat" 
/dev/sda2: LABEL="/boot" UUID="fe1f710e-50a7-48a0-9fa2-f15563010bb0" TYPE="ext2" 
/dev/VolGroup00/LogVol00: UUID="6e8cfa96-38b4-4bef-aef6-50b1635f206e" TYPE="ext2" 
/dev/VolGroup00/LogVol01: TYPE="swap" 
/dev/sda1: TYPE="ntfs" 
/dev/hda: LABEL="LG" TYPE="iso9660"

(In reply to comment #2)
> Created an attachment (id=368265) [details]
> dd if=/dev/sda3 of=vfat.img bs=1M count=40

Thanks. Unfortunately, it seems that FAT root entry is out of this dump (at offset 3747208192 or so). It means I can't reproduce the problem :-(

Please, try

   # BLKID_DEBUG=0xffff blkid -p /dev/sda3

btw, does the filesystem have any LABEL? I mean do you see any volume name in  Windows?

Now empty label. But I tried to assign some label with the same result.

[root@localhost yum]# BLKID_DEBUG=0xffff blkid -p /dev/sda3
libblkid: debug mask set to 0xffff.
reseting blkid_probe
ready for low-probing, offset=0, size=0
--> starting probing loop [idx=-1]
linux_raid_member: call probefunc()
ddf_raid_member: call probefunc()
isw_raid_member: call probefunc()
lsi_mega_raid_member: call probefunc()
via_raid_member: call probefunc()
silicon_medley_raid_member: call probefunc()
nvidia_raid_member: call probefunc()
promise_fasttrack_raid_member: call probefunc()
highpoint_raid_member: call probefunc()
adaptec_raid_member: call probefunc()
jmicron_raid_member: call probefunc()
vfat: magic sboff=82, kboff=0
vfat: call probefunc()
assigning LABEL
assigning UUID
assigning VERSION
assigning TYPE
assigning USAGE
<-- leaving probing loop (type=vfat) [idx=16]
--> starting probing loop [idx=16]
ufs: call probefunc()
sysv: call probefunc()
<-- leaving probing loop (failed) [idx=49]
returning LABEL value
/dev/sda3: LABEL="&M-^ZM-^]^CM-eM-^UM-cCM-`M-&M-K" returning UUID value
UUID="48F6-4212" returning VERSION value
VERSION="FAT32" returning TYPE value
TYPE="vfat" returning USAGE value
USAGE="filesystem"

Note that "&M-^ZM-^]^CM-eM-^UM-cCM-`M-&M-K" is a safe way how blkid prints unprintable chars. If you want to see real chars use

  blkid -p -o udev /dev/sda3

maybe the LABEL includes some utf8 chars,

[root@localhost ~]# blkid -p -o udev /dev/sda3
ID_FS_LABEL=_______C___
ID_FS_LABEL_ENC=\x26\x9a\x9d\x03\xe5\x95\xe3C\xe0\xa6\xcb
ID_FS_UUID=48F6-4212
ID_FS_UUID_ENC=48F6-4212
ID_FS_VERSION=FAT32
ID_FS_TYPE=vfat
ID_FS_USAGE=filesystem


In Vista And Centos 5.4 is "empty" label. But I remember this as something I saw in the past "_______C___". Perhaps previous versions of Centos showed that.

I've found this

https://bugzilla.redhat.com/show_bug.cgi?id=503228
https://bugzilla.redhat.com/show_bug.cgi?id=520207

This message is a reminder that Fedora 12 is nearing its end of life.
Approximately 30 (thirty) days from now Fedora will stop maintaining
and issuing updates for Fedora 12.  It is Fedora's policy to close all
bug reports from releases that are no longer maintained.  At that time
this bug will be closed as WONTFIX if it remains open with a Fedora 
'version' of '12'.

Package Maintainer: If you wish for this bug to remain open because you
plan to fix it in a currently maintained version, simply change the 'version' 
to a later Fedora version prior to Fedora 12's end of life.

Bug Reporter: Thank you for reporting this issue and we are sorry that 
we may not be able to fix it before Fedora 12 is end of life.  If you 
would still like to see this bug fixed and are able to reproduce it 
against a later version of Fedora please change the 'version' of this 
bug to the applicable version.  If you are unable to change the version, 
please add a comment here and someone will do it for you.

Although we aim to fix as many bugs as possible during every release's 
lifetime, sometimes those efforts are overtaken by events.  Often a 
more recent Fedora release includes newer upstream software that fixes 
bugs or makes them obsolete.

The process we are following is described here: 
http://fedoraproject.org/wiki/BugZappers/HouseKeeping

The same with Fedora 13

[root@localhost ~]# uname -a
Linux localhost.localdomain 2.6.33.5-124.fc13.x86_64 #1 SMP Fri Jun 11 09:38:12 UTC 2010 x86_64 x86_64 x86_64 GNU/Linux
[root@localhost ~]# cat /etc/issue
Omega Fedora Remix 13.1 (Carolina)
Kernel \r on an \m (\l)


[root@localhost ~]# BLKID_DEBUG=0xffff blkid -p -o udev /dev/sda3 | more
libblkid: debug mask set to 0xffff.
ready for low-probing, offset=0, size=132920524800
ready for low-probing, offset=0, size=132920524800
found entire diskname for devno 0x0803 as sda
whole-disk: NO, regfile: NO
chain safeprobe superblocks ENABLED
--> starting probing loop [SUBLKS idx=-1]
[0] linux_raid_member:
	call probefunc()
	buffer read: off=132920442880 len=64
	buffer read: off=132920516608 len=256
	buffer read: off=0 len=256
	buffer read: off=4096 len=256
[1] ddf_raid_member:
	call probefunc()
	buffer read: off=132920524288 len=512
	buffer read: off=132920393216 len=512
[2] isw_raid_member:
	call probefunc()
[3] lsi_mega_raid_member:
	call probefunc()
[4] via_raid_member:
	call probefunc()
[5] silicon_medley_raid_member:
	call probefunc()
[6] nvidia_raid_member:
	call probefunc()
[7] promise_fasttrack_raid_member:
	call probefunc()
[8] hpt45x_raid_member:
	call probefunc()
[9] hpt37x_raid_member:
	buffer read: off=4096 len=1024
	reuse buffer: off=4096 len=1024
[10] adaptec_raid_member:
	call probefunc()
[11] jmicron_raid_member:
	call probefunc()
[12] drbd:
	call probefunc()
	buffer read: off=132920520704 len=4096
[13] LVM2_member:
	buffer read: off=0 len=1024
	reuse buffer: off=0 len=1024
	buffer read: off=1024 len=1024
	reuse buffer: off=1024 len=1024
[14] LVM1_member:
	reuse buffer: off=0 len=1024
[15] DM_snapshot_cow:
	reuse buffer: off=0 len=1024
[16] crypto_LUKS:
	reuse buffer: off=0 len=1024
[17] VMFS_volume_member:
	buffer read: off=1048576 len=1024
[18] vfat:
	reuse buffer: off=0 len=1024
	reuse buffer: off=0 len=1024
	magic sboff=82, kboff=0
	call probefunc()
	reuse buffer: off=0 len=1024
	reuse buffer: off=0 len=1024
	look for label in root-dir (entries: 512, offset: -547759104)
	buffer read: off=3747208192 len=16384
	buffer read: off=1981372 len=16384
	look for label in root-dir (entries: 512, offset: 64871424)
	buffer read: off=64871424 len=16384
	buffer read: off=1073775612 len=16384
	look for label in root-dir (entries: 512, offset: -2128028672)
	buffer read: off=2166938624 len=16384
	buffer read: off=480794796 len=16384
	look for label in root-dir (entries: 512, offset: 849288192)
	buffer read: off=849288192 len=16384
	buffer read: off=126054416 len=16384
	look for label in root-dir (entries: 512, offset: -1582867456)
	buffer read: off=2712099840 len=16384
	buffer read: off=320495764 len=16384
	look for label in root-dir (entries: 512, offset: -883254272)
	buffer read: off=3411713024 len=16384
	buffer read: off=787282888 len=16384
	look for label in root-dir (entries: 512, offset: -369009664)
	buffer read: off=3925957632 len=16384
	buffer read: off=34530868 len=16384
	look for label in root-dir (entries: 512, offset: -113140736)
	buffer read: off=4181826560 len=16384
	buffer read: off=2087480 len=16384
	look for label in root-dir (entries: 512, offset: -113124352)
	buffer read: off=4181842944 len=16384
	buffer read: off=2087484 len=16384
	look for label in root-dir (entries: 512, offset: -113107968)
	buffer read: off=4181859328 len=16384
	buffer read: off=2087488 len=16384
	look for label in root-dir (entries: 512, offset: -113091584)
	buffer read: off=4181875712 len=16384
	buffer read: off=2087492 len=16384
	look for label in root-dir (entries: 512, offset: -113075200)
	buffer read: off=4181892096 len=16384
	buffer read: off=2087496 len=16384
	look for label in root-dir (entries: 512, offset: -113058816)
	buffer read: off=4181908480 len=16384
	buffer read: off=2087500 len=16384
	look for label in root-dir (entries: 512, offset: -113042432)
	buffer read: off=4181924864 len=16384
	buffer read: off=2087504 len=16384
	look for label in root-dir (entries: 512, offset: -113026048)
	buffer read: off=4181941248 len=16384
	buffer read: off=2087508 len=16384
	look for label in root-dir (entries: 512, offset: -113009664)
	buffer read: off=4181957632 len=16384
	buffer read: off=2087512 len=16384
	look for label in root-dir (entries: 512, offset: -112993280)
	buffer read: off=4181974016 len=16384
	buffer read: off=2087516 len=16384
	look for label in root-dir (entries: 512, offset: -112976896)
	buffer read: off=4181990400 len=16384
	buffer read: off=2087520 len=16384
	look for label in root-dir (entries: 512, offset: -112960512)
	buffer read: off=4182006784 len=16384
	buffer read: off=2087524 len=16384
	look for label in root-dir (entries: 512, offset: -112944128)
	buffer read: off=4182023168 len=16384
	buffer read: off=2087528 len=16384
	look for label in root-dir (entries: 512, offset: -112927744)
	buffer read: off=4182039552 len=16384
	buffer read: off=2087532 len=16384
	look for label in root-dir (entries: 512, offset: -112911360)
	buffer read: off=4182055936 len=16384
	buffer read: off=2087536 len=16384
	look for label in root-dir (entries: 512, offset: -112894976)
	buffer read: off=4182072320 len=16384
	buffer read: off=2087540 len=16384
	look for label in root-dir (entries: 512, offset: -112878592)
	buffer read: off=4182088704 len=16384
	found fs LABEL at entry 28
	reuse buffer: off=0 len=1024
assigning LABEL [superblocks]
assigning UUID [superblocks]
assigning VERSION [superblocks]
assigning TYPE [superblocks]
assigning USAGE [superblocks]
<-- leaving probing loop (type=vfat) [SUBLKS idx=18]
--> starting probing loop [SUBLKS idx=18]
[19] swsuspend:
	buffer read: off=3072 len=1024
	reuse buffer: off=3072 len=1024
	reuse buffer: off=3072 len=1024
	reuse buffer: off=3072 len=1024
	buffer read: off=7168 len=1024
	reuse buffer: off=7168 len=1024
	reuse buffer: off=7168 len=1024
	reuse buffer: off=7168 len=1024
	buffer read: off=15360 len=1024
	reuse buffer: off=15360 len=1024
	reuse buffer: off=15360 len=1024
	reuse buffer: off=15360 len=1024
	buffer read: off=31744 len=1024
	reuse buffer: off=31744 len=1024
	reuse buffer: off=31744 len=1024
	reuse buffer: off=31744 len=1024
	buffer read: off=64512 len=1024
	reuse buffer: off=64512 len=1024
	reuse buffer: off=64512 len=1024
	reuse buffer: off=64512 len=1024
[20] swap:
	reuse buffer: off=3072 len=1024
	reuse buffer: off=3072 len=1024
	reuse buffer: off=7168 len=1024
	reuse buffer: off=7168 len=1024
	reuse buffer: off=15360 len=1024
	reuse buffer: off=15360 len=1024
	reuse buffer: off=31744 len=1024
	reuse buffer: off=31744 len=1024
	reuse buffer: off=64512 len=1024
	reuse buffer: off=64512 len=1024
[21] xfs:
	reuse buffer: off=0 len=1024
[22] ext4dev:
	reuse buffer: off=1024 len=1024
[23] ext4:
	reuse buffer: off=1024 len=1024
[24] ext3:
	reuse buffer: off=1024 len=1024
[25] ext2:
	reuse buffer: off=1024 len=1024
[26] jbd:
	reuse buffer: off=1024 len=1024
[27] reiserfs:
	buffer read: off=8192 len=1024
	buffer read: off=65536 len=1024
	reuse buffer: off=65536 len=1024
	reuse buffer: off=65536 len=1024
	reuse buffer: off=8192 len=1024
[28] reiser4:
	reuse buffer: off=65536 len=1024
[29] jfs:
	buffer read: off=32768 len=1024
[30] udf:
	reuse buffer: off=32768 len=1024
	reuse buffer: off=32768 len=1024
	reuse buffer: off=32768 len=1024
	reuse buffer: off=32768 len=1024
	reuse buffer: off=32768 len=1024
	reuse buffer: off=32768 len=1024
	reuse buffer: off=32768 len=1024
[31] iso9660:
	reuse buffer: off=32768 len=1024	reuse buffer: off=32768 len=1024
[32] zfs:
	buffer read: off=131072 len=1024
	reuse buffer: off=131072 len=1024
	buffer read: off=135168 len=1024
	reuse buffer: off=135168 len=1024
	buffer read: off=139264 len=1024
	reuse buffer: off=139264 len=1024
	buffer read: off=393216 len=1024
	reuse buffer: off=393216 len=1024
	buffer read: off=397312 len=1024
	reuse buffer: off=397312 len=1024
	buffer read: off=401408 len=1024
	reuse buffer: off=401408 len=1024
[33] hfsplus:
	reuse buffer: off=1024 len=1024
	reuse buffer: off=1024 len=1024
	reuse buffer: off=1024 len=1024
[34] hfs:
	reuse buffer: off=1024 len=1024
[35] ufs:
	call probefunc()
	buffer read: off=0 len=1377
	buffer read: off=8192 len=1377
	buffer read: off=65536 len=1377
	buffer read: off=262144 len=1377
[36] hpfs:
	reuse buffer: off=8192 len=1024
[37] sysv:
	call probefunc()
	reuse buffer: off=0 len=1024
	buffer read: off=9728 len=512
	reuse buffer: off=15360 len=1024
	buffer read: off=18944 len=512
[38] xenix:
	buffer read: off=2048 len=1024
	reuse buffer: off=2048 len=1024
[39] ntfs:
	reuse buffer: off=0 len=1024
[40] cramfs:
	reuse buffer: off=0 len=1024
	reuse buffer: off=0 len=1024
[41] romfs:
	reuse buffer: off=0 len=1024
[42] minix:
	reuse buffer: off=1024 len=1024
	reuse buffer: off=1024 len=1024
	reuse buffer: off=1024 len=1024
	reuse buffer: off=1024 len=1024
	reuse buffer: off=1024 len=1024
[43] gfs:
	reuse buffer: off=65536 len=1024
[44] gfs2:
	reuse buffer: off=65536 len=1024
[45] ocfs:
	reuse buffer: off=8192 len=1024
[46] ocfs2:
	reuse buffer: off=1024 len=1024
	reuse buffer: off=2048 len=1024
	reuse buffer: off=4096 len=1024
	reuse buffer: off=8192 len=1024
[47] oracleasm:
	reuse buffer: off=0 len=1024
[48] vxfs:
	reuse buffer: off=1024 len=1024
[49] squashfs:
	reuse buffer: off=0 len=1024
	reuse buffer: off=0 len=1024
	reuse buffer: off=0 len=1024
	reuse buffer: off=0 len=1024
[50] nss:
	reuse buffer: off=4096 len=1024
[51] btrfs:
	reuse buffer: off=65536 len=1024
[52] ubifs:
	reuse buffer: off=0 len=1024
[53] bfs:
	reuse buffer: off=0 len=1024
[54] VMFS:
	reuse buffer: off=2087480 len=16384
<-- leaving probing loop (failed) [SUBLKS idx=54]
chain safeprobe topology DISABLED
chain safeprobe partitions ENABLED
--> starting probing loop [PARTS idx=-1]
	reuse buffer: off=0 len=1024
	reuse buffer: off=0 len=1024
	reuse buffer: off=0 len=1024
	reuse buffer: off=0 len=1024
dos: magic sboff=510, kboff=0
dos: ---> call probefunc()
	reuse buffer: off=0 len=1024
dos: <--- (rc = 1)
gpt: ---> call probefunc()
	reuse buffer: off=0 len=1024
gpt: <--- (rc = 1)
	reuse buffer: off=0 len=1024
	reuse buffer: off=0 len=1024
	reuse buffer: off=0 len=1024
	reuse buffer: off=0 len=1024
	buffer read: off=28672 len=1024
	reuse buffer: off=0 len=1024
	reuse buffer: off=0 len=1024
minix: magic sboff=510, kboff=0
minix: ---> call probefunc()
	reuse buffer: off=0 len=1024
minix probefunc failed
minix: <--- (rc = -1)
<-- leaving probing loop (failed) [PARTS idx=9]
returning LABEL value
ID_FS_LABEL=_______C___
ID_FS_LABEL_ENC=\x26\x9a\x9d\x03\xe5\x95\xe3C\xe0\xa6\xcb
returning UUID value
ID_FS_UUID=48F6-4212
ID_FS_UUID_ENC=48F6-4212
returning VERSION value
ID_FS_VERSION=FAT32
returning TYPE value
ID_FS_TYPE=vfat
returning USAGE value
ID_FS_USAGE=filesystem
reseting probing buffers
buffers summary: 803012 bytes by 80 read() call(s)

Fedora 12 changed to end-of-life (EOL) status on 2010-12-02. Fedora 12 is 
no longer maintained, which means that it will not receive any further 
security or bug fix updates. As a result we are closing this bug.

If you can reproduce this bug against a currently maintained version of 
Fedora please feel free to reopen this bug against that version.

Thank you for reporting this bug and we are sorry it could not be fixed.