Main screen fail - touchscreen won't work on main screen

Did you try removing the memory card?

I think I figured out the problem.  I had photos on the micro SD that I had taken with another camera, and they were over 1MB each, then apparently when I was assigning one or more of those photos to my contacts the phone just locked up trying to make that happen because the files were too big.  I typically have the favorite contacts widget up on my main screen, with my top five contacts in little gray boxes, and I think when the phone was trying to load the large file size photos to the little gray boxes on the main screen, it just failed and locked up.  It also saved those photos to the phone, rather than just on the micro SD, so I had to go into TKFE and delete them all separately, reboot the phone, and viola - my main screen is working again.