vouge won't answer most calls

[esskay]

It doesn't happen all the time, but a lot of the time I'll be receiving a call and I'll try to pick up (I've been trying both the green hardkey and the "answer" softkey with no difference between the two) and it will just hover on the call display for a few seconds before throwing me back to the today screen, and then I'll get a notification of "1 missed call". It doesn't matter if I'm in a high/low service area, and I never have a problem calling back.

I've tried upgrading the phone ROM from 1.668(?) to 2.13, and my service bars have seemed to jump up from previous in certain areas, but the problem is still there.

I love this phone, but this is almost a deal breaker for me: it's very annoying for both myself and whoever might be trying to get ahold of me. Does anybody have any idea what might be going on and/or how I can fix it?