The top is supposed to close up first, then the bottom pulls in. This is because the slide is driven from the bottom. Sounds like the slide motor is quitting too soon, or you are quitting too soon, on retraction.
If it is the motor stopping while you are holding the "close" button, then probably all that is needed is to find and adjust the limit switch.
If you have the screw-jack slide mechanism (likely for 2004) you have two slide motors that need to coordinate their movement, and there is a slip clutch on each of the two motors that starts slipping as torque rises at end of movement. A weak clutch could cause the problem you are having.