You are negative for HSV-2, the strain that usually causes genital herpes.
You have had previous infection with HSV-1, which is the strain that usually causes oral herpes (cold sores). About 60% of everyone is like you: previous infection with HSV-1 with no current symptoms. Most people get HSV-1 as kids, nonsexually, usually by slobbering on each other and sticknig hands in mouths and other messy things kids are wont to do.
You don't have a IgM result; IgM tests determine current, acute infection. If you have a positive IgM result, that means you are currently fighting the infection, and likely contagious.
Anyway, I don't think you have anything to worry about. As for your gf's Pap smears, those test for cervical abnormalities, inductively detecting HPV. HPV is the virus that causes genital warts and certain cancers. It is not herpes. If she is under 26, she ought to consider getting vaccinated with Gardasil, though. She will still need regualr Pap smears, but at least it's one more layer of protection.
I work for your friendly local health department.