[bedoig]

Will you go into your registry and verify that the value of "ForceCellConnection" at HKLM/Comm/Internet Sharing/Settings is "Sprint PCS" ? Alternatively, you can delete that key altogether, and you will again have the ICS drop down box where you can choose. For convenience, I usually just set the key to Sprint PCS.

There may also be an extension pointing at isext.dll in HKLM/Comm/Internet Sharing. That can be deleted that as well.

If all of that is already set as it should be, then you shouldn't be having any issues on the phone side. Can you connect over BT or Wifi (via WMWiFiRouter) using Internet Sharing?