First thing, just based on the information you've provided, is that you've not updated your Photoshop to 10.0.1, which Adobe released to fix bugs:
That it's failing now where it wasn't before might mean that you're doing something differently than you were before (we all change the way we do things as we learn new techniques, etc.) and running into an old bug that was dormant.
Other possible problems I can think of include the possibility that your system might be having some new problem. Windows Updates might have come in and changed the way it functions, or you might have installed something, maybe gotten a malware infection, or even are having a hardware problem.
I might suggest, if the above update doesn't help, that you look more deeply into your WIndows error logs to see if there might be other indications of problems brewing. For example, has your system been logging disk problems?
Lastly, maybe that long list of numbers you excluded might be meaningful to someone.
Thank you Noel...
I will check into any updates. I recently had to reinstall my Adobe products, and even though have done some updates since then, may have missed something.
Hopefully that will make a difference.
I might add, that I recently restored my PC back to factory standard, to clear a few issues that we were unsure were possibly malware, so felt this was a clean start. But yes, there have been several issues/glitches since then, things I have not seen before, and this was yet another one....