Alright I have taken some of your suggestions and I am still having the same problems.
I did a hard reset (push button on back) and went through the setup again.
I used the setting suggestions.
Currently, the router is not connected to the internet. I only have the necessary items connected to this router to try and eliminate all the variables:
1. windows media center pc
2. xbox (windows media extender)
3. switch
4. router
5. network tv tuner
The symptoms are the same. When the device is idle for a short period of time (few minutes), connection is lost between the xbox and WMC PC. Xbox restarts, then successfully connects to WMC PC, idle, connection lost, and the cycle continues....
Thanks for your help.