since you already had pre-existing issues with your battery terminals..change them both out with new ones. make sure the new hardware is tight. the original hardware that tightens the metal piece around the terminal wears out after a while.
looks like you already put a new one on the negative end (unless i read it wrong.)
dont know which terminal you picked up..but buy these http://www.oreillyauto.com/site/c/de...2111&ppt=C0005
un-bolt the nut on the positive end and slide this one in its place.
like i said, i only recommend this because you already have had issues with it. i would like to eliminate the battery contacts as a problem.
on another note..when you took your x to oreilly,did they check the battery on or off the truck? i would prefer off and have them check it on the stationary machine..not the portable one. the stationary one will charge and check it where the portable one only checks it. it can be low on charge and still check the battery. hence you still having problems turning it on. the big one will automatically charge it then check it.