I have a little experience with bug tracking systems such as FogBugz where help tickets are issues are (or can be) bugs, and I have some experience using a bug tracking system internally completely separate from a help center system.

My question is, in a company with an existing (home-grown) help center system where replacing it is not an option, how should a bug tracking system (probably Mantis) be integrated into the process?

Right now help tickets get put in for issues, questions, etc and they get assigned to the appropriate person (PC Tech, Help Desk staff, or if it's an application issue they can't solve in the help desk it gets assigned to a developer). A user can put a request for small modifications or fixes to an application in a help ticket and the developer it gets assigned to will make the change at some point, apply their time to that ticket, and then close the ticket when it goes to production.

We don't currently have a bug tracking system, so I'm looking into the best way to integrate one. Should we just take the help tickets and put it into the bug tracking system if it's a bug (or issue or feature request) and then close the ticket if it's not an emergency fix? We probably don't want to expose the bug tracking system to anyone else as they wouldn't know what to put in the help center system and what to put in the bug tracker... right?

Any thoughts? Suggestions? Tips? Advice? To-dos? Not to-dos? etc...