That happened to me all day yesterday - as soon as I hit save I got the uh-oh, but it saved anyway. I didn't report it either - I sure someone has by now. If it happened to all of us it's probably pretty widespread.
Its been reported but keep adding to the thread in bugs. I did and reported that about 2 of 3 times the rearrange "takes" but the other 1 I have to redo.
There have been multiple thread for the past couple days now, I've been trying to give them a bump if they fall to low. Admin said they were looking into it but it's a weekend.