While Ceton maybe the only company working on Windows Media Center Extenders at the moment there are many people are still using the Linksys Extenders. Over the weekend there have been lots of reports the Linksys extender freezing and locking up. This has happened before and it was caused by the extender not being able to connect to an update server somewhere on the Internet.
On thegreenbutton.tv there is a great tip get around the problem, all you need to do is to go to network settings on the extender and set the primary and secondary DNS entries to 0.0.0.0 and assign the device a fixed IP address. Once the Extender is rebooted it should be able to get to the host PC but not be able to get to the Internet and look for a non-existent Linksys update server.
Well done to the guys at TGB.tv for coming up with a solution.