Calling all plumbers...again.

[GattaFish]

Like Spence said. for a couple bucks I would start with wax ring and closet bolts. then see what you are left with. Hope fully that will do it. If you still see dripping when you run a sink check the sanitary adapter at the wall/floor where the P-trap/S-trap connects to the main drain line.

[Fishpart]

Could also be a bad seal on the vent stack where it goes through the roof. I had one that dripped only when the wind drove the rain a certain way. Some times the rubber flips over and holds water and sometimes they are just cracked.