Photoshop won't open files from Bridge or Explorer?

Is there a reason Photoshop would start refusing to open any type of files from Bridge and Window Explorer? If I double click a .psd file, nothing happens. If I drag the file over to Photoshop, it gives me the 'no' symbol, circle with a line through it. The only way to get files to open is to do it from photoshop.

It's done this a few times before, usually if I shut Photoshop down and restarted it would work, not helping this time though.

Nobody has had this issue? Interesting.

reset the preferences per the faq?

Tried that, doesn't help. Now even rebooting the machine doesn't help, where as before it would help temporarily.

did you get the dialog asking if you want to reset photoshop's preferences when you "tried" that?

Yes, I did.

I think I found the problem, it only wants to work with the 64 bit version.