I go to Comm Manager and in Internet Sharing window chose USB and O2 Internet. Then I click connect and GPRS is being dialed on Kaiser.
After this step I connect USB cable to PDA and a window indicating "Generic RNDIS" appears on PC. This changes soon to another one with text something like "Windows Mobile-based Internet Sharing Device is being installed".
And now - bad luck - this message is replaced by information that there has been a problem during installation and device won't run well. When I go to device manager on PC, there is Windows Mobile-based Internet Sharing Device with yellow icon (!) between network devices.
(If I try Internet Sharing through BT PAN, it works well - no problems with that one.)
(I run XP SP3 and Active Sync 4.5.0 (5096) are installed on my PC)