Ok, the weirdness continues.

While continuing the various restarts and calibrations, I got a memory error message - "operation temporarily discontinued due to low memory" or something to that effect. So, I took the memory card out and put it back in. (this memory card has never given me any trouble in the past, and I have not installed any new software in the past few days). When I restarted, my touch screen appears to work again! I opened Mahjong to test it (definitely a high- touchscreen game) and got the error message, "not enough memory in target location." However, when I hit "ok" the game did come up and worked fine. Now I get "not enough memory in target location" if I start a Mahjong game or if I close the program. And occasionally I get the "temporarily discontinued due to low memory" message.

If this were my Windows PC, I would think I had a virus. I will reflash when I get home tonight (found the link in another thread) but if you're having touch screen probs, it can't hurt to take out the memory card and put it back in. If you do that, please post whether it works or not and whether you get any error messages, if you don't mind.