Thanks for your reply.
Actually it doesn't matter at all whether a sound driver is being loaded or not. I have standard i810_audio built as a module as well as NVidia's nvaudio. My first order of business was, of course, to connect the machine to the network, so I didn't even bother with sound. Having discovered this problem, I played with loading either i810_audio or nvaudio before or after nvnet, but it didn't make a bit of a difference...
What makes me really frustrated is the fact that it works just fine on Windoze
It'd be nice to hear from an NVidia engineer...but I don't know if they actually watch these lists.
Learn from my experience, people, don't try to "save" money with intgerated motherboards!