I have constructed a menubar control which works fine under OS-X but not under Ubuntu Linux. I've a mixture of parent and child menus which do not produce an event in my event handling code. Under OS-X it all works great. Now, what I suspect is the QT4 code. Is it possible that I have not incorporated something correctly when I created my Linux system? I'm not a Linux expert, so I don't really know what I'm doing.
I've installed QT4 Designer, Linguist, Assistant and Settings using Ubuntu Software Centre. Is there something else I should have done/installed?