I tried to roll back to the Microsoft driver but couldn't. The rollback button grayed out after two rolls, and no amount of rebooting would give me another. So, I de-installed the entire Intel Proset software suite and rebooted.
It didn't get me back to a Microsoft driver, but it did get me working. This is strange. I am now on this driver: Intel, date: 10/4/2012, version 15.5.6.48
I was there before, and through every iteration up to 15.6.1.20. But now it is working fine at 15.5.6.48. How very strange. Is there something wrong with the Proset suite? Of course, I am sure the WIDI is gone, but I just want to connect reliably to the Internet on my expensive Ultrabook.
Web pages seem to time out if they sit idle to long, but it is working. Which make me thing that Intel is not trying very hard to fix this.