Thanks BeamRider but rando has already looked into that. It's not exactly what we are looking for. We tend to belive that VIA is misleading when using the name "I2C" for that port and that the underlying controller (VT1211) supports only the SMBus command subset.
We're investigating though and we could use all the help we can get. That means that if someone has an "inside" VIA connection we could use his/hers help.