Comment 6 for bug 390446

It does not "work" toolbars can only be reattached where they were detached at a pixel perfect position only. To truly solve this bug, it need to work right / as expected, not just allow you to undo the accidental move.

An other workaround is to switch from widescreen mode to normal mode and back (or the opposite). This feature would be useless if the toolbars were able to move correctly like other apps.