Adobe PS CS5.5 destroys files during active editing even without saving them.

Hey folks,

I encountered a very weird problem while working with Adobe PS CS 5.5 several times now. While editing an image it completely destroys the file im working with. Masks get lost, picture information is lost and even the colors are mixed up. There seems to be no specific pattern, it happens randomly and the outcome is random as well. Even when not saving the file, its completely destroyed and it cant be undone.

I don't think it's a software issue, as I completely removed CS and got a fresh install, error occurs again.

I'm using an iMac7,1 (Intel Core 2 Duo 2,4 GHz) and Mac OS X 10.6.8. We have about 30 other Mac systems arround and we dont encounter this with any other machine.

Could there be a problem with the hard disk oder ram?

Best regards

Marcel