Justananomaly, I'm really glad that this solved the problem. I just wanted to give a little bit more context here, since this might help others (and you helping others as well!).
The crash on startup issue was being caused by a corruption in the DRM store, possibly related with the recent hardware change. Zune accesses the store on startup and it was crashing due to this corruption. The change in the compatibility mode settings avoided hitting this problem, but it caused many other issues (particularly in CLR). Those issues were being surfaced as exceptions when Zune was accessing .NET 2.0 components (residing in mscorlib, ver 2.0.50727). Those unhandled exceptions were eventually caught by Watson which identified mscorlib as the faulting module.
The steps in the KB article resets the DRM store, fixing the corruption.
So, as far as I can tell (by Zune running smoothly now) there were no issues with CLR (.NET Framework). And we are currently working on addressing the corruption issues.
Thanks again for trying this out and sending the crucial information!
-Grimday
Rodrigo
Zune Product Team
.: This posting is provided 'as-is' with no warranties, and confers no rights :.