Comment 5 for bug 389639

You are right, this issue has nothing to do with virtualbox.

I have exactly the same problem with a fresh installed Ubuntu 9.04 machine. The problem with the cursor even appears in qt4-designer, changing the object name for example.

I have tested it with one of my own application. It don't work under Ubuntu because the cursor problem, but it works fine under Fedora 11 for example.