Allgunas posibles soluciones.

– in Users, we have ASP.NET Machine account

-Add the ASP.NET, IUSR and IWAM account to de Administrator Group
– deleted and recreated the virtual directory

– debug=”true” in web.config
– execute permissions = scripts only in virtual directory properties
– virtual directory name should be the same as the physical directory name
– ran C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\aspnet_regiis -i
– in IIS, the correct version of ASP.NET most be selected
– HTTP Keep Alive most be checked
– IIS most be configured to use Integrated Windows Authentication
– added http://localhost to the trusted sites for local intranet
– in C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\Temporary ASP.NET Files,  set full rights to “ASPNET Machine Account”
– disabled the loopback check
– verified we had Windows XP service pack 2 installed
– in IIS, verified that client side and server side debugging set to true
– verified that firewall turned off
– in IE, set security level to low.
– changed web pool to be the “Classic .NET AppPool”
– verified that in IIS properties, Document tab, I had Default.aspx

 Si poseen alguna otra solucione a problemas de debug en el servidor pueden dejarlas como comentario en este post.