I had to load the Widcomm 4.0.1.2101 to be able to do this in XP sp2 on my HP NC6000. Check out:
http://forum.gsmhosting.com/vbb/show...9&page=5&pp=15
This was with headphones, not a cell phone headset. But, the standard drivers HP provided did not give me any service options for my headphones. It would see them, I just couldn't do anything with them.