I need to step through some of the Core Authentication code (code that's originally in the Library files) but every breakpoint I set comes back with a message along the lines of "This breakpoint will never be hit. No symbols have been loaded". I've got the project in debug mode and the web.config has been changed to debug="true". I've rebuild the solution, deleted everything out of VSWebCache (though by looking at it it's not used for .NET 2.0 code), removed all the .pdb files and rebuild again. I'm at a loss. What am I missing?

I'm developing a module and its giving me the same problem.

That's the problem. I'm not getting any .pdb files. I've cleaned the solution, rebuild the solution and still no .pdb files. I don't remember running into this with 4.3.5 (the last version of the source I worked with) and can't figure out what I've missed.