Wow,

The problem is solved. turns out it was a defective driver for the integrated 10/100 connection. This was updated, rolled back, etc etc as one of the first troubleshooting efforts. Every diagnosis showed the driver working properly. I finally gave up and took it in to a tech I used when all else fails. He looked at it for two minutes, uninstalled the driver and reinstalled the same driver, wham bam, presto, better than new.

I'm on what is supposed to be a 12 Mbps connection, my XP unit downloads at 11.8, this little vista on the same modem and router, is downloading at 16.3, don't know how that's possible, but I ain't gonna try to fix it. Thanks for the feedback from all who tried to help, just wanted to let you know what the problem was in case you ever face the same thing.

Rob