Sounds to me that who ever changed the radiator fluid did not tighten the drain plug enough. Tighten it about 1/4 turn and watch it for about 3 minutes to see if it is still dripping, if so tighten it another 1/4 turn and so on.
Bill, enrolled member of Choctaw Tribe. 2005 Fleetwood/Revolution,AFE Filter,Aero Exhaust,Koni FSD shocks,KarKaddy SS. Progressive HW-50C.