Have you tried pulling the battery out?
I have the same problem with my new droid incredible. I've taken the battery out and restarted several times. The scenario is that my phone is in my pocket, someone calls, it prompts me to slide the bar up or down to answer or ignore......then i get a completely unresponsive screen. It will not answer my call.
This is definitely unacceptable. I can't have a phone that doesn't answer calls. This has happened a dozen times in the past 3 weeks.
Have you people tried doing a master reset?