unusual dei 530t problem

Ok, i am just now installing this thing in my personal car, now this thing has some hard windows, but after instalation, they all roll up fine, no problems even on lowest setting..,, BUT, when i try to get them to go down, the passengers goes fine, and the drivers stops about 2/3rd's down.. now this car DOES have a one touch drivers window from the factory, BUT that is in the switch.. so i'm possitive that the connection is between the motor and they system... still it seems strange to me that it would mess up going DOWN, sence it is harder to get a window to go up.. any help guys? i've tryed this on the highest settings, AND i even tryed removing the internal resistors to make it work even harder, still,, same problem, any help?