Ok so now we know what the problem is, just need to figure out how to fix the sucker. Looking at the first few lines of your report, the only difference to what I have (just ran the verifier again) is I have this;
Code:
[04/27/11,17:27:54] Install state for .NET Framework 4 Full: installed with no service packs.
I don't recall re-installing .Net 4 FULL, perhaps it was part of the windows updates.. so I recommend checking that updates are all up to date, I know you said earlier that they are but doesn't hurt to double check, and if so, then try grabbing and installing .Net 4 Full from microsoft.
Cheers
Goanna