The error I got originally:
“sgx error (background gpu access not permitted)”
Indicated something is trying to access the gpu while the app is in background, such an access is prohibited, according to Apple:
Sorry to say, but I am not sure why the pause/resume from the CCDirector has something to do with SimpleAudioEngine, since pause/resume inside the CCDirector do not pause/resume the audio engine, nor audio engine depends on it.
Just found out a thread here:
It seems like they were not sure why either.