Microsoft Symbol Server for .NET - problem

I've configured Visual Studio to use Microsoft Symbol Server and it downloaded PDB for System.dll, and then loaded it successfully, but there is no any source code files - only PDB. Any ideas what开发者_开发问答 is wrong?

the symbols are not source code... if you want to debug with framework source see http://msdn.microsoft.com/en-us/library/cc667410.aspx

Plz don't consider this as advertisement ;) But this task can be solved with Reflector 7 Pro. It allows to debug FCL assemblies.