Should have added the following information:
 2.6.13-1.1532_FC4smp #1 SMP Thu Oct 20 01:42:06 EDT 2005 x86_64 x86_64 x86_64
GNU/Linux

 cat /etc/hp/hplip.conf
# hplips.conf

[hpiod]
port=50000 (registered IP port)
# port=0 (dynamic IP port)

[hpssd]
port=50002
# port=0

[hplip]
version=0.9.6
# jdprobe=0

[dirs]
home=/usr/share/hplip
run=/var/run

Are you seeing avc messages in /var/log/messages or /var/log/audit/audit.log?

No, I did not see any avc messages in /var/log/messages. I looked around all the
other files in the /var/log directory and could not find anything logged.

I did run these tests:
SANE_DEBUG_DLL=128 scanimage -L and it completed without finding any issues. But
running scanimage: 
scanimage: open of device hpaio:/net/Officejet_7300_series?ip=10.2.2.10 failed:
Error during device I/O

Does this work when you 
setenforce 0
?

Since I'm now running in permissive mode I did a setenforce 1. Then ran
scanimage and it failed. Then did a setenforce 0. Re-ran scanimage and it works.
So I checked the /var/log/messages file and found:
Oct 31 20:33:26 douglas dbus: avc:  received setenforce notice (enforcing=1)
Oct 31 20:33:26 douglas dbus: avc:  received setenforce notice (enforcing=1)
Oct 31 20:33:30 douglas su(pam_unix)[10344]: session closed for user root
Oct 31 20:33:37 douglas hpiod: ParDevice::nibble_read failed: Input/output error
Oct 31 20:33:38 douglas hpiod: unable to connect to scan err=13 port 9290
JetDirectChannel::Open: Permission denied
Oct 31 20:33:39 douglas hpiod: device cleanup
uri=hp:/net/Officejet_7300_series?ip=10.2.2.10
Oct 31 20:34:12 douglas su(pam_unix)[10427]: session opened for user root by
(uid=1001)
Oct 31 20:34:17 douglas dbus: avc:  received setenforce notice (enforcing=0)
Oct 31 20:34:17 douglas dbus: avc:  received setenforce notice (enforcing=0)

Ok, can you install policy sources

yum -y install selinux-policy-targeted-sources
cd /etc/selinux/targeted/src/policy
make enableaudit; make load
setenforce 0
Try to scan.
See if you have anything in /var/log/messages or /var/log/audit/audit.log

When you are done testing you can do a 

make clean; make load

yum -y install selinux-policy-targeted-sources
cd /etc/selinux/targeted/src/policy
make enableaudit; make load
setenforce 1
scanimage - which failed
See if you have anything in /var/log/messages or /var/log/audit/audit.log
type=SYSCALL msg=audit(1131166220.319:6823): arch=c000003e syscall=1 success=yes
exit=6426822 a0=4 a1=2aaaae0c2010 a2=6210c6 a3=0 items=0 pid=32266
auid=4294967295 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0
comm="load_policy" exe="/usr/sbin/load_policy"
type=AVC msg=audit(1131166304.466:6824): avc:  denied  { name_connect } for 
pid=32350 comm="hpiod" dest=9290 scontext=system_u:system_r:hplip_t
tcontext=system_u:object_r:port_t tclass=tcp_socket
type=SYSCALL msg=audit(1131166304.466:6824): arch=c000003e syscall=42 success=no
exit=-13 a0=5 a1=413fa850 a2=10 a3=0 items=0 pid=32350 auid=4294967295 uid=0
gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 comm="hpiod" exe="/usr/sbin/hpiod"
type=SOCKADDR msg=audit(1131166304.466:6824): saddr=0200244A0A02020A0000000000000000

What is port 9290?  Is this a standard port or is this a port set by the user?  

Dan

Looking at the code I see the following

./io/hpiod/jetdirect.cpp:static const int ScanPort0[] = { 0, 9290, 9291, 9292 };

So I will add these three ports.

If you add the following lines to 
/etc/selinux/targeted/src/policy/domains/misc/local.te

portcon tcp 9290 system_u:object_r:hplip_port_t
portcon tcp 9291 system_u:object_r:hplip_port_t
portcon tcp 9292 system_u:object_r:hplip_port_t

Then do a mail load, it should allow the scanning to continue.

Closing due to lack of response.
Looks like this was probably added, according to the last comment.