Tools quit working in CS

I have had the stamp tool and the burn tool quit working in CS. The file has a background layer and a second layer that has a mask. Things work fine for a while but then the tools quit working. Trying to do a burn or stamp on either layer does not work. The tool icon is correct, the selected layer is correct, but nothing happens as the tool is used. I suspect that other tools would also show this problem. System is Win XP pro with 1.5 Gb of RAM. File is large, about 500Mb. Seems that others have had this problem. If I save the file, close it, then re-0pen it, all the tools work okay. I do not need to restart photoshop CS.

Any ideas?

Dennis

Do you use a wacom tablet - some of the old ones have conflicts with Photoshop CS. You need to update the drivers. If you are using a wacom tablet, unplug it and see if that clears up the problem.

Cheers,
Rose

(and make sure the stylus isn't resting on the tablet while trying to use the mouse!)

Thanks, I will check this out (about the tablet). I have a tablet that is made by another manufacturer, but was not using it at the time. However, it was plugged in and active. The sylus was not on the tablet.

Dennis