I found out some more info. The bulbs are fine, the ballast is shot (as I figured). The ballast is rated to run two 36w bulbs (PL 36 if I remember correctly). On the ballast there is a diagram and some info. The label said, "KMB Electronic Ballast". It is pretty small... small enough to fit inside the light fixture. I'd say it's a little larger than a pack of cigarettes.
There are red and black wires connecting into the ballast and two endcaps are connected on the other side. There are some more numbers on the ballast that I didn't write down. Lastly, the power cord from the wall connects into the fixture (near the on/off switch) and I believe first enters the other ballast, then is connected somehow from there. The red and black wires run the length of the fixture from the other side underneath the reflector.
The fixture is about 2 years old. There is no manufacturer name on it -- it's not made by one of the mainstream brands. I *think* it is either made by Aqua Clear Aquatics or maybe Catalina Aquarium. The whole fixture supports 4 bulbs, 2x36w and 2x18w. The configuration looks like:
Hope this info will shed some light.