Comment 7 for bug 691741

Found exact way to reproduce:
1) Open any application
2) Maximize it - its titlebar goes into the top panel, thats ok so far
3) Click the Close button in the top panel to close the window - I guess window state is saved
4) Reopen the window - as the window state is rememebered as maximized, the window is restored as such, but its own titlebar is not hidden, thus it does have a titlebar in the top panel and one in the window.