Steps to reproduce:

1. Start debugging an application (I used a simple GUI for that)
2. set a breakpoint in a class you still can hit - and stop at it
3. check whether an expandable object is listed within Locals and Expressions (at least 'this' should be...) - leave this unexpanded
4. press continue debugging
5. switch back to the Locals and Expressions view and try to expand 'this'

If you don't wait and eventually hit another (or the same) breakpoint everything is fine and 'this' shows the inner content.
If you wait (40s) then Creator says gdb isn't responding - wanna wait longer or stop debugging session?
(If you wait longer - without pressing the "Give GDB more time..." button another widget is popped up after further 40s and so on..)

This doesn't happen when using CDB instead of GDB.