Ok, I know the problem now, I alloced a new CCWindow that isn’t released at the end and thus it stays as a white screen.
NSWindow *fullScreen = [[CCWindow alloc] initWithFrame:displayRect fullscreen:YES];
Since my knowledge of alloc and release is sadly limited I found the following solution:
Go to the CCDirector void CCDirector::purgeDirector()
and add exit(0); right after the following lines:
// delete CCDirector
This is maybe not an ideal solution, but until someone is kind enough to explain how it is done properly, this will do.
Thank’s to all who helped.