I keep running into this waiting for civ freeze in my C2C games, all on the slowest setting. One game it happened in 9000BC, the other ~2500BC. There's no error file I can find, but the game just won't progress even if left for hours.
Saves below:
http://forums.civfanatics.com/attachment.php?attachmentid=325089&d=1341327657
Saves below:
http://forums.civfanatics.com/attachment.php?attachmentid=325089&d=1341327657