First, I want to say that I did not create any of the files I have listed here, I just found them abroad and I have compiled this information as a guide to get your Bluetooth Stereo Sound Quality at its best.
1) Download and Install the A2DP BT Hack cab file.
2) Soft-Reset.
3) Download and Install the SRS WOW HD 1.21 cab file.
4) Download the WOWHD ARM Panel.cpl and place it into the /Windows
directory on your Diamond.
5) Soft-Reset.
Generally Speaking, doing these steps should give your stereo bluetooth headset much better sound quality.
To adjust your bass, treble, etc. use the SRS WOW tool - after installing it you can find it under your system settings.
The A2BT Hack cab file makes changes to your registry, which you can view in the text file included in the zip. The one regedit that is going to have the biggest effect on your sound quality and conversly how much skipping you have is the Bitpool. The Higher it is set, the better the sound quality will be, but the more the music will skip, and vice-versa. If you you adjust your bitpool beyond the max or min supported values be sure to change those values accordingly.
ENJOY!
A2DP_BT_Hack.zip
SRS_WOW_HD 121.CAB
WOWHD_ARM_Panel.cpl.zip
Enjoy!