1) I think we'd need to see your code and get an idea of the file sizes you are working with to help with this. Is it possible your assets are too big for the memory you have on your Android device? And, did you make sure to put all your media in the '/assets/media' directory with the bytecode file?
2) I think the looping on playmusic not working in an android is a known problem (search to check for this).
3) If you update anything in the assets/media directory or rebuild the app when the Eclipse interface is open, you need to refresh the project in Eclipse. Right click on the project and click on 'Refresh'.
Finally, what version of AppGameKit are you working with?
I've been catching up since I returned from vacation, otherwise I would have responded sooner.
Cheers,
Ancient Lady
AGK Community Tester