Dave, I tried saving, exiting and reopening Vue with the problem scene, but it was just the same afterwards, I couldn't move objects to another layer. Btw, hitting "flush history" should erase the possible undos from the memory, and therefore should be enough to clear the undo instances you refer to? As I said, it's a a fairly complex scene, and I can't work in wireframes on it. On the other hand, I don't NEED to change layers, it's just that I like to keep my scenes tidy, so I know where things are when I look for them, instead of all objects dropped in layer 1, in ultimate chaos!