Water on front seat floor when air conditioner on. Took it to a repair shop and the drain is not plugged up.

Did they determine if the drain is still attatched to the air box? Because the box is either damaged (unlikely), the drain plugged (they say its not) or the drian tube is detached (definately possible)

Edit... I say detached because all the cars I have worked on has had a rubber hose from the box to the floor pan... it can be kicked loose and is under the carpet. Usually on the passenger side of the transmission tunnel or center hump.