Vista 64 Media Center Crashes on Program Start

I have Vista Ultimate 64 bit. My machine had been running fine for a

while now. But Monday when I tried to use my Xbox 360 as an extender,

which is what I do every single day, it showed the connecting screen,

then just stopped at a black screen. I went to the computer and tried

launching Media Center from the desktop and it crashed right away with

the following error details.

Media Center has stopped working

Description:

Stopped working

Problem signature:

Problem Event Name: CLR20r3

Problem Signature 01: ehshell.exe

Problem Signature 02: 6.0.6001.18000

Problem Signature 03: 47919e0e

Problem Signature 04: Microsoft.MediaCenter.UI

Problem Signature 05: 6.0.6000.0

Problem Signature 06: 480ebd70

Problem Signature 07: 33ba

Problem Signature 08: 0

Problem Signature 09: System.NullReferenceException

OS Version: 6.0.6001.2.1.0.256.1

Locale ID: 1033

I have been absolutely loving my Vista Media center and can't stand

having to use my cable provided dvr. Any assistanced would be greatly

appreciated. Thanks!

As another side note, Media Center is still recording scheduled shows.

And I can watch them in Windows Media Player. I just can't open Media

Center on the desktop or through the XBOX 360