I haven't seen this one yet on the forums... I'm having a bit of trouble with the turn sometimes advancing when I'm clearly in the middle of something. To be very clear: I have autoturn disabled. I would expect that this means I MUST press the TURN button or enter/spacebar to advance the turn.
But some other behavior that will occasionally cause the next turn to happen:
Opening up the research screen, changing techs, and closing it again.
Finishing Diplomacy.
Moving ships (may or may not be the last ship with moves left).
I feel like it randomly happens at other times, but I can't remember with certainty, and it's tough to reproduce because it only happens once in a while (five or eight times in as many hours of otherwise bug free gameplay). When it does though it is very frustrating.