I'm using custom firmwares since CM9 nightly. At first everything worked fine, but since some point of CM9 development and later on all CM-based firmwares I'm having a strange bug. When somebody calls me and I answer, the call screen shows without a call timer. After 3-4 seconds the call either starts or (much more often) hangs up and shows that I have a missed call. The person calling me just sees that I've hung up.
Sometimes (very rarely) phone restart fixes it for 1-2 days, but then everything comes back.
Sometimes (very rarely) phone restart fixes it for 1-2 days, but then everything comes back.