thanks you for your help Jani. I tried to manually close it, but it still woudn't fully close. at first i thought it was because there was this wax/melted plastic-like stuff on the track, but after taking that off it still was stuck. after that i notice these clips, one on each track. one of them was pushed in while the other was pushed out. so, i pushed the one in and the roof closed like it always did.

interesting how we learn things, huh? =P