Hey! I just came here to report the exact same thing! I have never had this happen before until just within the last hour! It hangs and does just what Orio says. I don't have any hair, just some objects sitting on a table with nine lights. I had just deleted a bunch of lights. I saved, bebooted, and the same thing happened. I am using a bucket size of 300. I'm going back to make sure my bucket size isn't too big.