Sort of solved.
The ASUS MB came with several utilities. I wanted just the temperature probe software but it only came bundled with several other ASUS utils... including some kind of network tweaker. After uninstalling the suite the network speed returned to normal.
I have no idea why...
Well. Since I had time today and got impatient I reformatted the drive and reinstalled windows 7.
My phone and tablet (running android jellybean) are fine. But something with windows 7 and WMI seem to be capping the upload speed.
I swapped out the MB, CPU and memory in my rig. I did not reinstall windows 7. I was pretty impressed that this worked as well as it did but I have one nagging problem... The network upload speed has suffered a lot. It's not just throughput but the initial "connecting" handshake seems to...