Xcode not stopping on breakpoint

I found the problem, Somehow the "Show Disassembly when debugging" was enabled in my Xcode which creates that problem. When I disabled it, all my debugger stopped in my source code.

You can find it under Product->Debug Workflow->Show Disassembly when debugging

Edit

In the latest Xcode it is under Debug->Debug Workflow->Show Disassembly when debugging

Xcode 6:

Go to Build Settings and make sure your "Strip style" is set up as "Non-Global Symbols" and not as "All Symbols"