edit: I had originally posted a broken build earlier last night so if gapless playback or flac playback doesn't work download it again from the link below.
Before I started working on this project, I had not touched java in a few years. I had completely forgotten how easy it is to leak memory in java. Memory issues are not something you typically associate with a language that uses garbage collection. There is a good article on the android dev site about preventing memory leaks: http://android-developers.blogspot.com/2009/01/avoiding-memory-leaks.html
Anyway I went through every single class in my app and made sure things properly are cleaning up. If you were having issues with 0.21 definitely give this a try.
Download 0.21.1 Alpha here
-Caught exception thrown in the compatability view if the audioengine doesnt properly load
-Properly handle errors that occur in the audioengine library
-Improved memory usage and stability
-Audioengine: fixed bug that prevented the decoders and file readers from being
properly cleaned up causing a major memory leak