I notice that my bluetooth dongle works well with osx while I'm surfing the internet. So I think my problem is with my xp installation. So now I think it might have been the bluetooth services or drivers running under xp that are causing the sluggish performance.
Even on ethernet, while using the bluetooth dongle to stream music to my headset, I find web browsing sluggish, but then again opening up Word and Excel causes the streaming sound to drop off for 1 or 2 seconds.
Is there any program (besides task manager) that I can use to see what's causing the sluggish performance ?