Making changes to panels twice

Any time I make changes to a panel, I have to do it twice. Adding is mostly OK, but if I delete something from a pane and then click update, it reappears until I delete it again and then press update.
It also happens when reordering displays and pane contents. I reorder them, click update and then they pop right back to where they were. I have to do it again and then when I click update they stay there.
This is a major bug. It doesn't make the module unusable, but it sure is a real pain.