Update
HP Support is worthless when out of the 1 year warranty. They won't even talk to you. One may think this isn't a big deal but it does say a lot for not supporting their own products.
After reinstalling the drivers, I was not asked to reboot my server. After a few days I had a need to take the server down and up and *poof* duplexing was back. Go figure. So, I will assume that the driver update needed a computer reboot.
