Windows Small Business Server – TS Gateway Authentication issue

We recently implemented a new SBS 2008 server for one of our clients.  A user was going to be working from home and wanted to utilize thier corporate office desktop to get some tasks done.  They were able to authenticate to the Remote Web Workplace webpage successfully,  but were unable to connect to their Windows 7 desktop computer.  Every time they attempted to do so, their account was rejected with an error message: “The logon attempt failed”

I discovered the problem was due to an incorrect setting within IIS.

Here’s what I did to correct the problem:
I went to IIS Manager → Sites → SBS Web Applications → Rpc → Authentication.  There I found only “Basic Authentication” was enabled.

Enabled “Windows Authentication” then ran an IIS reset. When IIS came back online, I was able to connect via TS Gateway to the server and at least one workstation. I connected and disconnected multiple times and it had no problems. The end user verified they were also able to authenticate without error, and gained remote control of their Windows 7 computer.