Thanks for the tips, Art. The "parked" current drain is reading 27 milliamps - pretty close to what you said. So I think there are only a couple of possibilities.

Bad battery, dying.
Charging system not working well.
Perhaps I did leave something on while away.

I'm not sure what you meant by a clean top. Are you thinking that gunk across the top of the battery would act like a conductor?

On a side note: this is a battery I got from Mr. Tire (Lee Hwy in Arlington Va. in case anyone is in this area) only because the prior owner had a warranty- and I still paid $60.00. Now I really regret it. When I explained this looked like a bad battery still under warranty they indicated that they would charge me a required $50.00 fee to check my charging system in order to rule out the possibility that my "car killed the battery". I'm not making that up. So, I argued a bit and it seems like they might do something to check their battery but at this point I would gladly pay $50.00 simply to never be within ten miles of people like that. Bad karma. So, I went over to Advanced Auto and the guys there at least tried to help with their battery tester (but I think they typed in the wrong values). I'll check the specific gravity of the cells. It looks like a can buy one there for about $90 - online. All the plates are covered with electrolyte and I am wondering if this is the kind of battery I am supposed to top up. The caps have a slot and the cap can be unscrewed but somehow I thought this was "maintenance free" since the caps cannot be pulled off without a tool.