DotNetNuke: debugging module when running dnn under iis express?

Does anybody know how to set this up? I have under module's project properties start url as 开发者_如何学JAVAhttp://localhost:16555/default.aspx which is what webmatrix shows as my dnn site. I tried using locall IIS express web server, tried custom but it always shows that symbols were not loaded, and it showing them as being loaded from temp asp.net folder, not from the dnn bin.