Hey, Doc.
I don't know much, but I don't think I have any network sharing set up. What I *do* have is a SlimServer icon beside "Other" at the bottom of System Preferences. That's where I go to make any changes to the SB or Transporter, but I log into the wireless router to make changes to the network.
I'll echo avta's question -- do you have SlimServer downloaded and loaded on your computer? I had to follow the instructions that came with because OSX is still so foreign to me.
Speaking of which, if it weren't for my wife taking care of the network connectivity stuff, I'd still be where you are.

I doubt that helps any, but let me know if there's anything on my machine you'd like me to look at.
-Jim