Visual Studio 2005: ASP.NET debugger doesn’t work with Internet Explorer 8 installed
I had yesterday this very odd problem and again Google came to rescue. Here is a solution: http://weblogs.asp.net/abdullaabdelhaq/archive/2009/06/01/VS-Debug-Problem-with-IE8.aspx
This problem only apply to VS 2005 and prior.
You can download ready to import registry file below:
Fix for Visual Studio and ASP.NET debug problem with Internet Explorer 8 (84)
(185)

