James,
.Net Framework 3.5 did not want to go quietly. After using Add/Remove Programs to remove .Net Framework 3.5 I still had porblems with Hoster 4.05 crashing time and time again. I have never seen Hoster 4.X act so strange.

I had to do a system retore back a few points to get things in working order.
Just trying to save you some grief.
Jim
