This has been happening in Photoshop for years (decades maybe).
No one has been able to nail it down yet.
Best guess I've ever had is that it's some kind of memory corruption due to problems in other operation that manifest as a failure in the event loop. Specifically, I had it once and a display driver update cleared it right up. That doesn't mean that it's always a display driver problem, but it wouldn't hurt to ensure your display driver is up to date.
What video card do you have? Generally you want to go to the web site of the maker of the card and download/install their latest driver, but AMD's latest released driver isn't working well with Photoshop and there's a specific version (13.3 beta 3) you'd want if you have an ATI card.
Thanks for your fast reply! I thought that might be the case searching around for anything similar.
I have an NVIDIA Quadro 2000 and it does appear to have an older driver version than the one currently available. Before I download it, do you know if NVIDIA is having the same issues with compatibility as AMD?