All color management operations depend on a minimum of two profiles. Simply viewing a document requires a profile that describes the document and one that describes the current display. Other operations involve three or even more profiles. If you run into issues that don't appear to be a result of operator error, it's likely that one or more of the profiles involved is a weak link. Use a process of elimination to troubleshoot problems. Test each profile in isolation and change one thing at a time. You're likely to find the culprit much quicker than you would by flailing around and changing multiple parameters willy-nilly.
Color management isn't a panacea, and it doesn't remove the need for intelligent human color correction. It's just a useful tool that provides a solid floor for you to stand on when you make your (hopefully intelligent, certainly human) corrections.