I also have this issues, it's like the milestone had a output buffer for audio too small.
It is strange that only a small amount of users are reporting it (maybe doesn't happen with bluetooth headset?).
We should see what our milestones have in common.
I'm using the stock audio player
I do have home++ as my home screen
I do use many widget::
- Mini Info
- Stock music
- Power Control
- Smooth Calendar
- Weather Bug
- Wind Status (show credit of my operator)
- HandCent
- Lite settings Profiles
I do have also this other process that are not widget but are in memory:
- Net counter
- K-9
- OSMonitor
- Ring Guard
- Gmail
- Battery Graph
- sipdroid
Lets see if we can understand the cause

Cya