I thought the inventory saves on toomanyitems were game save slots, so when one of my friends was over I clicked "save" then we proceeded to take turns building random stuff out of everything I had. By the end of it we were using creative mode to try out all the planes in the planes mod, and finished off by using the bomber on my house and farm and all of our buildings.
When I clicked "load" nothing happened. I thought "huh" and then restarted the game, still nothing. It took both of us a second to realize what happened and he just started laughing at me.