PS: Unable to use keyboard shortcuts

This has been bugging me for awhile, and I couldn't for the life of me figure out why it's happening, or how to change it. I can't seem to use any keyboard shortcuts: save, open, copy & paste, etc. Also, I can't use the arrow keys to nudge the text/pictures either, which is really annoying because I hate having to constantly turn off the 'snap to' option (I like to use it a lot since it can be really useful sometimes).

I checked the memories and I didn't find this anywhere, so I'm hoping maybe someone can help me? I use Photoshop CS, if that's of any help. Thanks!