i investigated further:
- it only happens with my se mw600, the se vh410 (or a slightly older modell) works completely flawlessly - are they using different profiles? (btw listening to music is flawless)

- it happens with power-kernel v50 AND the standard omap of pr1.3

- it was better with kp v49; but i reflashed between using v49/50, so i cant really tell

- sometimes it starts stuttering and stops transferring audio/voice, sometimes it does it without stuttering; the headset stays connected for a few seconds and then disconnects

any idea what can cause the problem?
and i will try kp v49, wether it is kernel-related or just another program.