G5 Duo crashing too much any help suggestions

I recently got a G5 Dual 2.3 and installed 10gb ram

I had a mirror door G4 with 2gb ram before that crashed once in a blue moon, even when processing 200meg files it was ok - slow but OK

This one is turning off way too much for my liking

Last crash I had iTunes, iPhoto, Adobe bridge and firefox running

Clicked on a page link in Firefox and it closed itself down, the grey/black screen from the top with restart message

I've left it on for some time not using it to see if was a heat issue or something as the last couple have been while using small programs

Here is the message:-
Interval Since Last Panic Report: 423237 sec
Panics Since Last Report: 3
Anonymous UUID: 2FC304F8-BA07-40E1-BD11-7ADE84CF7817

Sat Jun 6 11:57:06 2009
panic(cpu 0 caller 0x000E4F48): "buf_setupl failed\n"@/SourceCache/xnu/xnu-1228.12.14/bsd/vfs/vfs_cluster.c:1290
Latest stack backtrace for cpu 0:
Backtrace:
0x0941EA3B
backtrace terminated - unaligned frame address: 0x526F0A5C

Proceeding back via exception chain:
Exception state (sv=0x68c3ea00)
PC=0x93006788; MSR=0x0000F030; DAR=0xA03A3A54; DSISR=0x40000000; LR=0x92E9A370; R1=0xBFFFEAD0; XCP=0x0000000C (0x300 - Data access)

BSD process name corresponding to current thread: Unknown

Mac OS version:
9J61

Kernel version:
Darwin Kernel Version 9.7.0: Tue Mar 31 22:54:29 PDT 2009; root:xnu-1228.12.14~1/RELEASE_PPC


Any help or ideas please as I need to make this a working stable machine