That's great you got it working.

But just few comments. Build 3500 has an issue with Sleep that the headset takes a long time to wake up. It also has an issue that randomly you can get Memory error (I think it depends on what other software you have running). It would be great if you could get this working with Build 3100.

Also installing build 3100 followed by 3500 makes no sense. Every file 3100 installs is replaced by 3500. Every registry change in 3100 is replaced by 3500.

Try HatOnCat's instructions with 3100 first (it's more stable).

P.S. Recommend staying away from Motorola headsets and Jabra 250. Not that they are bad headsets. They are just more unpredictable with these phones. Sony and Plantronics.