Photoshop CS2 constantly crashing

I am having a very strange issues with CS2 at the moment, out of nowhere the program seems to be crashing every hour or so. Sometimes the menues will just stop working (while the tools work fine) other times it will crash to desktop with the following error in the event viewer:

Faulting application photoshop.exe, version 9.0.0.0, faulting module ntdll.dll, version 5.1.2600.5512, fault address 0x0000120e.

(googled this without much luck, closest i got was a virus but this is a clean install and i have already ran a hijackthis scan, avg and adaware scan which all came back clean)

I have also tried changing the swapfiles for windows to a 2nd drive to see if it was a paging issue.

All drives have been checked for errors and defraged.

The pc spec is as followes:

Dell precision 530mt
2 xenon 2ghz cpus
1gb ram
windows xp pro sp 3

Any advice will be greatly recieved, thanks

tried resetting the preferences per the FAQ?

Yes have tried that, to make sure i have done it again and it stil is doing the same as before.

Anyone else offer any advice on this matter as it is quite urgent i get this issue sorted?

k, closest i got was a virus but this is a clean install and i have already ran a hijackthis scan, avg and adaware scan which all came back clean)

I think that means to reinstall the app (photoshop). what concerns me is that ntdll.dll is an important system file. hoping you don't wind up having to do a full format/system install to solve your problem. start with photoshop, and apply any patches. also make sure windows is fully patched via windows update...

Thanks for your help Dave.

Unfortunatly I have already tried the reinstall of photoshop, as you can imagine its one of the first things i tried.

Going to try cs3 to see if thats more stable, if not then its a reprep on this system unless anyone has any thing else left to try?

sorry.