Quote from MS BlogNews Channel
"For many Photoshop users, there is a horrible bug in Adobe Photoshop that causes the program to stop importing from the clipboard. You’ll be using the software for hours or even days without a problem, and all of a sudden you won’t be able to copy and paste anything into it at all, with your only option to close and re-open Photoshop.
Thank Goodness there is a solution, because this has been driving me nuts! I upgraded to Photoshop CS3 over the weekend, and the bug is ten times worse on CS3 under Vista than ever before."
It was driving me nuts as well and I couldn't decide if it was my PC, XP, Photoshop CS2, or CS3. After some research it became clear that my version(s) of Adobe Photoshop had this clipboard bug.
Andreas Wivestad has the easy registry fixes on his site for download to repair this bug in Photoshop versions CS, CS2, and CS3. After applying the registry fix from Andreas, my Photoshop was running smooth and trouble free. It's a relief knowing that this bug is now squashed, well at least until the next one comes along.