HTC 8125 / 8100 / MDA (USA) / K-JAM / P4300 (Wizard)

I've been having an ongoing problem with my MDA freezing with about half of the calls that I recieve while my phone is locked. Sometimes, it will show that I have a missed call and the keypad will be in the background, and the whole screen becomes garbled. This happens in different situations, and after it gets into this state it won't respond to any buttons so I have to soft reset it. I was wondering if anyone else has had this problem and if they had fixed it? I'd rather not turn off the phone lock feature.