6 days ago I wiped my s2 and installed CM 11 from nighty builds. I have only 1 problem:
When I'm in call, If I receive a concurrent call the first call automatically goes in pause, i hear the "pause tone" and i cannot continue talking with the first callee if I first don't close the communication with the second one.
This problem is present only in latest nighty (in fact the M7 based on 4.4.2 was working like a charm.)
Do you experience the same problem?