The SP1 release of VS08 regressed some functionality compared to the original release, in a couple of critical areas. As a result it is highly likely you'll need the following two patches for it. I know many of our team who hit these issues, cursed, came to me (because I am the "VS guy" on the team) and then became happy when I pointed them to these:
Update for Debugger Stepping and Breakpoints - note if remote debugging be sure to patch those binaries too.
Hope you find these as useful as we did.
Please note it has been many years since I have worked on VS itself, so don't go crazy asking all sorts of other VS-related questions in the Comments. This is what I know. And that is it: I'm just a customer like you these days.