This has been driving me mad for hours now! Whenever I run my PocketPC compact framework app I cannot debug it! None of the breakpoints will stop, each breakpoint just shows as an empty circle instead of a solid one.
So, what was the solution? I tried deleting all PDB files on my hard disk but that didn't do it. In the end manually deleting all of the files previously deployed to my PPC did the trick. Maybe VS couldn't overwrite them or something? No idea, but at least it works now :-)