Try deleting the preferences (FAQ says how). You might have a layer mode set to something other than normal as well.
I had this happen as well. I exited PS, then opened it up again and they worked (actually, the Stamp tool only so far as I know).
Actually the problem seems to be that I am using a Wacom Graphire 2. If I try to use the mouse do do a quick touchup, it just doesn;t do anything. But, if I switch to the Stylus Pen, it works fine. I can also then switch back to the mouse and that works too. If I close and re-open CS, the mouse no longer works for these tools again, until I use the Stylus Pen.
I did download the latest driver from Wacom, but that does not seem to fix the problem.
<silly question>you’re not setting the pen down on the the pad when using the mouse are you?</sc>
No, the pen is in its stand. I also discovered that just changing the zoom resets the mouse from working. Again, if I use the pen for a second, the mouse then starts working again.
I sent Wacam a message, but have not heard back yet.
I have had this happen with both the stamp tool and the burn tool. They just quit working. If I save the file, close it, then open it again, all the tools work again. This is not a layer problem. I checked to make sure that the proper layer was selected.
Dennis