Full Screen Mode Crashes?

[Tupac Shakur]

When I enter full screen mode (Alt + Enter together) and then tab out to iTunes, the Blade and Soul client crashes for good and I can't click anything on my desktop, not even anything in Task Manager - the only thing that I can click is my taskbar/toolbar at the bottom, so I sign out/Restart the PC to fix it and it's annoying - happens all the time and I need to be in full screen mode for my game to run smoothly.

 

Is there a way around this? Can I not tab out at all?