Cut and Paste not working on Mountain Lion

I downloaded Mountain Lion on the first day of its release, upgrading from Lion. Ever since then My cut and paste functions havent been working. It would function after the first 10 to 15 minutes, but soon after that time passes, I am unable to copy/cut paste anything either via the mouse or typing commands. This is very frustrating. I would have to shtdown and turn the computer back on just to get the function back temporarily. Does anyone have a solution for this?!

Also, I just updated my Mountain Lion to 10.8.1 as of yesterday, and its still happening!!

Lastly, I verified permissions and reinstalled the OS, still happening...