As I posted a while ago, ASP.NET 2.0 has some upgrade issues to reckon with.
Now there's a new upgrade wizard to test, so lets get some Nasty Sites upgraded :-). You might want to throw in a website that uses reflection on Web Page classes, just for fun... (those classes won't be available until a page has actually been loaded... so reflection those classes will not work until you loaded the page or ascx control)
Anyway, get the full info here, and the download for the wizard over here.