I usually use GIMP, because it works well with my DigiPro tablet, and Photoshop doesn't. Except, as you see here, those times when it doesn't.

The problem seems to come up whenever I switch from Photoshop to another program (e.g. Firefox), stay there for a period of time, and then switch back. It just draws a line from wherever I put the pen down to wherever I lift it.

If I plug the tablet out and back in, it goes back to regular drawing, but I lose the pressure sensitivity.

So I restart Photoshop and it works perfectly. Switching to another program and switching right back seems to work fine. But it's staying on another program for at least 5 seconds that seems to screw it up.

GIMP doesn't give me any problems whatsoever, so I stay there. I don't know which has the steeper learning curve, though, and I have no idea if switching to another program will automatically produce higher-quality art. Just one of those things that niggles me.