First thing I'd say is look at how your memory is allocated per program and which programs take priority when they are open.

Your specs look pretty good to me, I would suggest upgrading your graphics card to some thing that has a min of 385MB of memory, 128 used to be standard, but we all know what the computer world is like...

The first thing I did was 'reallocate' my memory and PS CS2 seems to be fine now.
Also it helps to close and reopen the program after editing about 20/30 photos as this clears the RAM and virtual mem of the PS 'stored' stuff. Plus I find rebooting my system at least every 3 days goes a long way to winning the battle.

I don't know what you're free space is like but it might be something as simple as having all of your pics stored on a External HDD and run PS on your internal HDD - hence more virtual memory. I read that in Pro Photographer mag, so I did it and it def helps as well...

My 2p that's probably only worth 1p...

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