I was using a copy of 2006, so tried my 2005 disc and had the same. Also tried a friends.

I then bought a new 2008 disc to try and that's the same.

Good point re CD v DVD though.....might explain why the CD is working to some extent.

I did have problems some months ago with it not working and took the disc out and it was all steamed up! Was a cold-ish (UK) day.

Possibly related....looks like a trip to the dealer.