I have the KiDiGi dock with a HDMI connection port too.
Before I attempt this mod, the first thing I was to clarify is the USB mode. Whenever I plug my phone into the dock, it starts charging, however the USB mode is not detected - so i cant sync or do file transfers, however if I pull out the USB lead from the back of the dock and plug it directly into the phone, the USB mode is detected straight away. So with this said I know the cable is fine, and the ports its connecting to are fine and my drivers are fine. It seems the dock must not be connecting the USB data pins or something?
Can someone clarify this?
If you look at the pics xSilv85 posted, you will see that the HDMI model does not have the USB data pins at all - only USB power is present. So the HDMI model apparently can't do data transfers.