[LAU] Bluetooth A2DP pitch shifting

I have been lately using a Bluetooth A2DP headset to listen to music. Every now and then, it drops pitch! It slows the music down, by as much as a semitone, for several seconds, then comes back slowly. I rather like the effect; it's like an old cheap analog vynil turntable with a bad motor or worn belt. What could be causing this? The signal path is Ogg Vorbis files to Android phone (obligatory Linux content!) to A2DP stereo headset. Also, I'm very much enjoing the best of 2010 mix! The quality of the music is excellent. I have it on shuffle along with the latest Radiohead record, and I cannot tell which is the multi-mega-superstar-major-label-millionaire-rock-band release, and which is a guy in his bedroom knocking stuff out on his laptop for fun in spare hours after work. Linux audio is definitely as ready for prime-time as the prime-time is. I digress, but nonetheless, I will BOX THE EARS of anyone who diverts my precious thread into discussions of apocalypse, conspiracies, or revolution. You have been warned :-) -ken