Debug symbols not loaded

I spent a frustrating hour yesterday trying to figure out why I couldn’t hit the breakpoints (“Debug symbols not loaded”) in my class library.  I added and removed references and build options until I could think of nothing else to do.  Then I said, even though it’s not pointing at the GAC version (this is a DLL shared by multiple apps), let’s see what happens when I remove it from the GAC…BINGO, problem solved!  I still don’t understand why it was using the GAC version since all the projects in my solution were referencing each other as “project references”, but that solved the issue.