Real programmers don’t sleep! 
@HeiKoDea Are you using Codea Scratchpad. I seen in the documentation that supportedOrientations() isn’t supported with Scratchpad.
Well I found out: When I start the project via Air Code, supportedOrientations doesn’t work. Starting it right on iPad from Codea it works as expected.
@Ignatz: Have to simulate sleeping for my wife only to prevent calling me zombiebabe all the time…
@All: Thanks for your suggestions and time!
Regards, Heiko