I can only recommend frequent savings.
Apart from a hardware issue, you might consider a Windows/Vista issue.
Maybe you should post in the Photoshop forum as well.
What input device do you use? Microsoft Intellipoint drivers have been known to cause these issues as do some Logitech drivers for their advanced mice with configurable buttons. Can you provide more insights?
The hardware issues to consider. Bad RAM, poor connection, inadequate graphic card, poorly seated graphic or other card or RAM (could have happened if you installed something recently or if you perhaps moved the computer, your monitor can be going belly up as well.
This can also be a corrupt or damaged or ill advised install of a free font that is flakey.
Back to the hardware inadequate space on the scratch disk or the scratch disk could be going to a crispy toasting.
Or some other hard drive is going bad.
Does not sound like preferences that I agree on.
Now this would be really bad but there is one other thing that might make this happen if it is indeed hardware, the processor is frying.
I go for a poorly seated card or bad cable or connection.
I use a PS/2 hp mouse that came with my computer. I had a logitech before but I never had a problem with it.
I also have a WACOM tablet but I've had this problem before I installed it, and that's a USB.
Should I try to fiddle with the graphic card? I haven't installed any fonts recently.
I don't think anything is frying - I think I'd have bigger problems if that were the case.
Perhaps the mouse that would actually be the best scenario of all the possibilities.
You might try it but make certain it is seated properly before rebooting.