Below are some of the common issues that you may run into developing for Zune and the best way to try and fix the issue. This is meant to be a living FAQ so it will grow over time. Please make sure that you have taken a look at the XNA Game Studio 3.0 Readme http://creators.xna.com/XNA3CTP/readme_xna.htm which answers many questions.

How do I quit a Zune game?

Holding just the back button for a few seconds anytime while inside a Zune Game will exit the game, and reset the Zune.

I can't connect to the Zune with XNA Game Studio 3.0 CTP.

First, Make sure that you are running the Zune 2.5 Firmware on your device by going to settings | about | zune. If you are running 2.5 try rebooting the Zune by holding up and back at the same time for about two seconds. If this fails to work try rebooting your machine.