Got out my caulking gun and ran a bead of silicone around each of the three floor vents, under the vinyl flooring and re-installed my vents. This seemed to stop the air from blowing under the flooring. I also noticed that the duct work is also somewhat "crushed" between rear and center vent.(Right above the water tank!!!) I wonder if they still might cover this under warranty even though it has expired? It seems to be a common problem! I know the dealer will deny it, but who would I contact at Keystone?