Watch out guys. The map overwrite bug has returned. I'm not sure how it happened exactly but I definitely overwrote a custom map. The name says one thing, and it loads up a different map. Luckily I only lost about an hour of work. I highly recommend saving progressive versions of your maps every couple of hours at least.
Probably the same thing it was before where if you let it auto-load your map from temp files and then use Save instead of Save As..., it overwrites some other map file. I really can't believe they didn't fix that. 343 needs to dedicate a resource to just forge, because they dropped the ball in this area badly.
I didn't encounter this problem in Reach but I heard about it. If I, for instance, edit my map, go to customs to test something, and go back to forge immediately, is this when I'm susceptible because I did not select it from the menu for forge?