I have an AT&T Fuze with the original, stock Windows Mobile 6.1 installed. I have tried repeatedly on two different machines to get Internet Sharing working over either bluetooth or usb. No dice. Finally, I stumbled on this blog: http://stevenharman.net/blog/archive/2008/10/03/windows-mobile-internet-connection-sharing-hack.aspx. The important part wasn’t how to hack the registry. What I needed was to know that the AT&T ISP connection needed to point to wap.cingular instead of isp.cingular. I made that simple change and my connection worked flawlessly! Hopefully this helps someone else.
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