if you are having a problem as describe in this post:
asp.net mvc debugger throwing SEHException
then the solution is:
if you have any application from Trusteer (like rapport or anything ) just uninstall and reboot your system, it'll work fine ... found this solution here:
http://forums.asp.net/t/1704958.aspx/8/10?Re+SEHException+thrown+when+I+run+the+application