I have a similar STB, a Mele A2000 with an A10 chip. I too have noticed that AVIs and MP4s have audio/video sync issues on ICS. I thought the problem might be reading the files off my ext4-formatted SATA drive, but it looks like it's likely ICS. I really don't want to fall back to 2.3 since I want to use Mizuu which requires 3.0+. I've tried the 7/14/2012 build of XBMC for Android, but the playback stutters really bad and it crashes while updating the library. Any other more recent builds available?