I recently was playing around with the debugger, and had some
problems, too. What helped a lot, was step 2):
1) run debugger;
2) set the first breakpoint to the first line of your code;
3) c[ontinue] -> debugger should break at your first line;
4) delete this first breakpoint and set your desired breakpoints,
maybe even some disp's;
5) c(ontinue) -> debugger should break at your desired points;
6) v(ar) l(ocal)