I'm no ratings maven, or expert in hip hop/R&B music, AND I don't get back to Birmingham very often, but everytime I do pass through, I do a band scan. 95-7 Jamz sounds just like it did when I lived in the area over 5 years ago. And when I say the same, I don't just mean the same liners and stuff, I mean I keep hearing 5 year old music that is not necessarily becoming of a contemporary music station.
If that's still the case today, that could explain the slide - fatigue. I feel the same issue with The Eagle. It's just one of those old classic hits format that will go through ebbs and tides as the masses get burned out.
I quit listening to Magic when their sound quality went to pot and they ditched a lot of the oldies.