Main menu Qt Creator disappeared

[inger]

Thank you for your reply.

I'm using a Oracle VM VirtualBox with Ubuntu 11.10 . the OS for the main PC is Windows 7.

I can see the tiltle bar (Ubunntu [Running] - Oracle VM VirtualBox) in the upper left corner.
when I restart the program it is still the same result.
When I tried Alt-F the File menu popped up. Then I could use the mouse cursor for getting the other pop-up menues.
When I tried 'Ctrl-F (For getting the Full screen mode) The title bar for Ubuntu disappeared. The menu for the Ubuntu then is at the bottom of the screen, just like is it meant to.

Thank you ChrisW67, you put me in to the right track
When I pressed Alt + W, I saw the Full Screen was chosen. When I removed the tick for that, everything is fine again!