I had every skin do that, aero or not. I was told to disable WFX5 and they worked again. Mine were the shutdown menu, admin menu, and recent menu. Funny that the control panel menu didn't have a problem (I use menu style not window style on those) Too bad, I really liked WFX5. I will run it again on the next release - it is beta after all.
etc. If the screen shot had been taken with a plain background you would have been able to see it better. If you go to my thread (something about WB) you can see a clear example.