Comment 10 for bug 1226298

I think this is a feature. I mean, if somebody calls you 5 - 10 times in a row, how annoying isn't that? I would certainly like to block that person for a while. ;-)

Just kidding. I can reproduce it here, and I think it's PulseAudio related (or even further down in the audio stack).

I also noticed two things:
 - If you wait a few minutes without calling the phone, it seems it resolves itself.
 - If you wait a few minutes while calling (just let it ring), eventually the dialog will come up, but not the ringtone.