Windows 7: Dell Bluetooth awful

I have a Dell Studio laptop and went to use my bluetooth headset with it for the first time last night. I have been using it with my iPhone for months so know it is capable of lovely stereo sound.
However with the laptop is is just plain awefull. It is mostly through the left speaker and certainly not in stereo. Jusr playing music through mediaplayer results in crackle, misses, and just plain silence at times.

I have the latest dell drivers for it and can't find any real settings that would affect it.

Any hints gladly welcomed. The headset is a MM100.