After mapping out my continent, I put the maps into frames on a wall to see what the whole map looked like. When I picked them up, they flew off and disappeared. I was in my cave/hidey hole, which is under a mountain. I went searching to see if I could find them (desperate because I'd just spent two in-game weeks making those maps). I found one outside about thirty blocks away, and the other one on the top of the mountain, about fifty blocks away, straight up. Their frames were sitting next to them. They flew through the mountain! Curious, I made another map, and tried again, with similar results, except I never found the map. Was working fine in 32d.