Hiccups in Bluetooth audio output

I was very excited to finally get A2DP capability with the arrival of Leopard. However, I'm having very disappointing results and I'd sure appreciate some help to find a solution. Here's what's happening:

Everything works as advertised except that every so often (maybe 20 - 30 secs or so) there's a brief "bzzzt" in my Bluetooth headphones (Motorola S805). It's short but it's annoying enough and frequent enough to really disrupt the pleasure of listening to music.

I've become convinced that it's something to do with the data stream internal to my PowerBook because I've done a lot of experiments to eliminate RF interference and I've tried it with several different Bluetooth receivers with identical results.

Checking the activity monitor, I think I can see a correlation between the "bzzt" and spikes of data writing to disk but not all spikes result in a sound, just some of them. I've closed all possible applications that I can think of but this doesn't change anything. I've got 2GB of memory which should be more than plenty.

Does anyone have any ideas of anything I could tweak to make this work properly, maybe increase a buffer size or something...?

Thanks! Very frustrating - so near yet so far!