slamming the door is to unstick a non functioning motor, it sounds like your regulator is striped (the teeth are ground off of the big gear) possible the plastic gear on the motor split but they usually don't move at all, a striped regulator will usually work fine till you get to the bad spot, if the window is stuck down you can probably get it closed by getting someone to pull up on the glass while you hit the switch
all america wants is cold beer warm cat and a place to take a poop with a door on it