The paper style like the MAP using is supposed to be kept wet, if not the fuel will evaporate and the oil left will eventually gum up the paper.
it may just be me but I feel the biggest mistake people make is not using large enough fittings on the Vent side of the system. The fuel pressure from pulling fuel through system really grows when you restrict how much air you can pull into the tank. If the fuel leaving the tank is overcoming the the ability to pull air in things start to go bad.