I have been working for some time on a single player offline server, building minecart lines everywhere, and building some pretty impressive stuff. Long story short, I was building a skyscraper to adorn one of my tracks with and I had just finished, saved and exited the game properly. When I logged back in, I was floating (I was in creative) in the middle of nowhere. I figured I had just moved somewhere different, so I looked around and found one of my village hubs. Turns out, I was right where my skyscraper should have been, and everything that was in that certain area was gone. My tracks, buildings, ect. My village was still there, and my other work was still there, but a huge chunk of my world seemed to have reset itself. Not only that, but every time I log in to that specific game, at a certain point in the village, another duplicate layer of whatever is on a certain line is built again. I'm up to four layers of village stuff.
I'm scared to log back in to that world. I'm also scared to log in to any other server. My questions are, could this be a corrupted chunk? If so, how do I go about fixing this? Also, is it safe to make other worlds, or go into other maps without having to worry. I don't want anything crazy to happen to my other maps as well. This one was hard enough to see messed up.
I'm running windows 7 right now, 2.0 GB RAM installed memory, 64 bit OS, Inter Core 2 Duo CPU E6550 @ 2.33 GHz.