place this in the units init field
this setpos [(getpos this select 0),(getpos this select 1),7]
the last number, 7, is how many metres in the air the unit is.
u can cahnge it to anything you like
dont worry about changing anything else
just fiddle around with it until you get the right height
also place this in the init field to stop the unit from hitting the deck all the time
this setunitpos "up"
hope that helps
Tim