file reverting to previous Ide session[resolved]

[idle]

I fired up the ide this morning and looked at my code only to notice that one of my files was restored to the previous days work.
It's not like I'd simply had vivid coding dreams or anything as I can clearly see the code where I posted it in the forum.
It's the second time this has happened and I've got no idea how or why.

So WTF happened to cause the code to revert to the previous session?
It's not like didn't save the file, I saved it multiple times and I always save any work before closing the IDE.

The only things I can think of is maybe it's some syncing issue with Ubuntu One service.

As it turns out it is the Ubuntu one service.
sudoing nautilus reveals numerous files with the extension .u1conflict.x