Hi, we are testing a dual boot system with Fedora Core 2 and Windows 
XP SP 1 or FC 2 and Windows 2003 on the same hard disk, our hardware 
configuration next...

Motherboard AX4BS
Micro: P4 1.7 Ghz
Ram: 256 Mb
Hard Disk: Maxtor 40 Gb

The partition table:
Disposit. Boot      Start         End      Blocks   Id  System
/dev/hda1   *           1       20369    10265503+   7  HPFS/NTFS
/dev/hda2           20370       20571      101808   83  Linux
/dev/hda3           20572       44951    12287520   83  Linux
/dev/hda4           44952       79408    17366328    f  W95 Ext'd 
(LBA)
/dev/hda5           44952       45991      524128+  82  Linux swap

First we instal Windows, and then install Linux, in a default 
install, but the grub can't boot Windows with this error....

Booting 'Windows XP'
root(hd0,0)
file system type unknown, partition type 0x7
chainloader +1

Here our groub.conf

default=0
timeout=10
splashimage=(hd0,1)/grub/splash.xpm.gz
title Fedora Core (2.6.5-1.358)
        root (hd0,1)
        kernel /vmlinuz-2.6.5-1.358 ro root=LABEL=/ rhgb quiet
        initrd /initrd-2.6.5-1.358.img

title WindowsXP
root (hd0,0)
chainloader +1

Was tested on three differents moderns hardwares and the problem is 
still there.
Any ideas??