Windows Media Center Store Update Manager Crashes
If you're messing with the MCE guide settings in Vista you may end up with Windows Vista Media Center Update Manager constantly crashing. It will crash everytime you try to update your guide or when performs a scheduled guid update.
In my case, I was configuring the guide to work in New Zealand with with xmlTVNZ. The problem is that somehow Media Center's database (which is, curiously, a Sqlite database) gets corrupted and one of the fields can't be converted into a DataTime.
The solution is to delete the file C:\ProgramData\Microsoft\eHome\mediacenterdatastore.db. If the file is locked, you will need to shutdown the media center process as well as the ehrec.exe (use the Task Manager to kill the process or the Services manager to shutdown all the services with names starting with "Windows Media Center").