What version of AE, what codec are you rendering to, what size and color space, what kind of audio files - mp3, wav, aiff.., what do you mean by out of sync at full resolution- does the image go faster than the audio, it studders...?
Answer the above questions and you may get a solution.
Sorry for not being really clear with my question. But i all ready fixed it, not sure what the problem exactly is but here's what went wrong.
And i guess the .mp3 was the problem.
But the weird thing is that it only happened today, last days it was just fine.
The audio was slowed down (pitched down), so everything was out of sync. But it was very minor, so at first i even didn't knew it was slowed down. Also the audio track was exactly the same length as before.
Not sure how to call it but if i cmd+click on my timeline and move the timeline over my project the audio was perfectly in sync. Really weird, cause then it also should be out of sync.
Also checked the frame rates but there was nothing wrong with it.
What i did was rendering it out. Somehow the audio was normal again, and everything was in sync again.
Only in after effects it was out of sync.
Curious what it could be, but next time i will stick to .wav files.