Nexus S Woes
I had the exact same story and errors as tdog1o1, and the ONLY fix I found useful was on an mp3 forum.
" I had code 43 problems with my usb ports until I found a thread on MSI's website. My front panel usb ports connected to a 9 pin usb header on the motherboard. Only 8 pins are needed. If pin 9 has a black ground wire then remove it. I didnt give this fix much hope but it fixed my problems! "
After many hours of driver installs, front usb port changes, and a dozen reboots, this actually worked!
I merely used the USB at the back of the computer and Voila!
Looks Wind Slash nailed it at the beginning of this thread.