Okay -- got Transmission up an running. I am getting DL speeds in excess of 120 kB/s -- about the best I've ever seen over my DSL connection -- and it does not seem to be choking my web surfing speed.
So if anybody is reading a thread that excited little interest, and no value-added responses (NOT flaming here, I appreciate you padding the response count, but "I am not having your problem" and "I can't remember how I fixed this problem", don't really count as help or advice) and is about to roll onto the 3rd page of the forum: I heartily recommend Transmission (look at versiontracker) as a less complicated and much faster alternative to Azureus.
And yes, you do have to set up port-forwarding if you are behind a router. And no, I don't know how to set up port forwarding on any router except a 2wire homeportal -- and I only figured that out after hours of google searches and lots of trial-and-error.