Music slows down when on stereo Bluetooth headset!

I thought I was just imagining it when I noticed that occasionally, music playing on my iPhone would change pitch (slow down) noticeably whenever I'm on my Altec Lansing BackBeat 903 headset. I've since confirmed it by comparing the use of said headset with my Apple In-Ear headphones. There is no such pitch change when using the Apple headphones. I've noticed that the Bluetooth headset tends to make the iPhone perform slower, whether it's launching apps, changing settings, etc.

I didn't think it was possible to have such pitch changes in music stored on a flash drive. Is it possible that the current draw of a Bluetooth headset dramatically degrades the performance of the iPod portion of the phone?