I'm using a Nokia BH-216, If the n900 is not connected to wifi the sound quality is decent, if connected to wifi but no active transfers, is somewhat choppy, making a SIP call over wifi is nearly unusable because of bluetooth choppiness.

Making a SIP call on the n900 over 3g has decent sound quality.

On my n800 I can make SIP calls over wifi using bluetooth headset with decent sound quality.

/me thinks the n900's wifi might be causing interference with the bluetooth. If that is the case is it something which is a hardware limitation, or can the situation be improved through the software?