In Generation IV and V, more Ribbons were introduced, where they are viewable in the Pokémon's summary screen. While primarily obtained in Super Contests, Ribbons could still be obtained in a variety of ways.
All Ribbons show up on ONE page, no matter what. One tab. I have many experiences with Ribbons like Relax, Smile, and those Ribbons in D/P.
Are you sure that you actually got the Ribbon? You should try again.