I have the same problem and I finally found an explanation here http://social.msdn.microsoft.com/Forums/en-US/vsdebug/thread/8cbfb45a-4cc2-4604-abda-f892635f7833[^] And some other usefull info here : http://blogs.msdn.com/greggm/archive/2005/11/18/494648.aspx[^] Hope it will help you