Fullscreen mode on OS X - wrong scaling in submenues

• When using the graphics option "Fullscreen: ON":
  • The start screen gets displayed alright
  • When entering a submenue (e.g. "Muliplayer"), the display will be scaled in a way that only the lower left part is visible. The menu is not usable.
  • When pressing ESC and going back to the main menu, the scaling will be alright again.

• Fullscreen works as expected, when using the fullscreen feature of OS X.

• Was still working with 1.7.10