Let me give a little background here just incase any of the information is relevant:

I did a routine coolant change on my '92 N/A in november (i think) by pulling the lower radiator hose. put it back on and filled up the radiator. went for a drive and turns out that i now have a waterfall of coolant coming out from where the lower rad hose attaches to the rad. hurried home and deduced that it was an original lower hose and needed replacing. all said, 4 gallons of coolant and a new hose, and the leak seemed to go away. Although I don't drive it hardly at all. well, anyway just a couple of weeks ago before the holidays (about a month or so later) i moved it to a different spot in the apartment complex, all of 100 feet or so. I turn the truck off and now the drip is back! (but slower, like a drop per second) then magically 3 hours later, it stops??? i figured that the lower rad hose clamp is a bit lose so i tighten it and it hasn't leaked from there since. I have not moved the truck since then.
this afternoon, it is warmer here than it has been in a few days and now coolant is leaking but from a different spot!! the problem is, i can't tell where it is coming from. keep in mind that i have not started the truck.
The leak seems to be coming from the area around the back of the oil pan near what i think is the rear main seal, on the passenger side near a black cylinder that looks like the starter. hose is dry, water pump and thermostat are much farther forward on the engine so i don't think that is it. can anyone help?
I've attached some pictures so that hopefully someone who knows what they are looking at can tell me. you can see coolant on some of the bolts.

http://i133.photobucket.com/albums/q...o/IMG_0526.jpg
http://i133.photobucket.com/albums/q...o/IMG_0524.jpg
http://i133.photobucket.com/albums/q...o/IMG_0523.jpg