Hi Chris,
Hahaha, that's because I had it replaced when it went south a few years back. I was having an awful time resetting it, and finally one day, I pressed hard enough that the reset stick broke. Don't recommend going the route that I took, because the trip odometer is not available as a separate item. It comes as part of a set that also includes the speedo and circuit board, to the tune of $1000. In case you were wondering, the circuit board, speedo, and trip meter in your car is only a couple years old.
Later, another member in my area had the same problem, and we had a used one, so we opened it up and replaced it. The old one, after we studied it had nothing wrong. Just needed lubrication. After lubrication, it worked fine. Mine was unrepairable though, due to the broken stick, and as Steve says, it's on his porch now. 
The problem manifests itself as a hard to reset trip odometer, then it gets worse to the point you can't reset it at all.
