tethering problem

[inusa2]

I did follow the instructions by this link:
http://forum.ppcgeeks.com/showthread.php?t=30265

I made all changes in the registry and also disabled the Phone as Modem connection.
After a few soft reset and hard reset, I still cannot tether successfully.

Here is what I did for the tethering:

1) open IE from Handset and browse any page, data connection is on,
2) connect handset and pc with usb cable,
3) activesync run automatically in PC and showed connected
4) from handset's comm manager,click Internet Sharing, Status still
disconnected, and the connect button is grey.
BTW, in Comm Manager, any time when I connect handset and PC with USB cable,
the Data Connection will be automatically off.
What's the problem?
Any clue?
Do I miss any configurations ?

Thanks.