Tom,
What you are desribing presently is an issue of insufficient run time to dry out the house. This problem would be exasperated if you had a larger system (like an 8 ton). You need to have someone verify that the staging is functioning on both the A/C unit and the blower. The system needs to be operating at it's lowest capacity to lengthen run cycles.
There is a way to slow the blower down to its circulation mode speed which might help. If you want to try this, just simply remove the Y1 wire from the furnace control board. If there are two wires connected to the Y1 (YLO) terminal in the furnace, remove them from the terminal and connect them together with a wire nut. This will allow the A/C to run on low stage and the blower will run at its lowest cfm level.
Joe
"When you perceive zoning not as a bandage but as an enhancement, you truly understand the dynamics and limitations of forced air heating and cooling"