closing adjustment on astro roof???
 

Can anyone here tell me if there is any way to adjust the closing portion of the astro roof on a 92 Eldo? The owners manual shows one switch to open and close the roof, but the one I have has three separate switchs. One is marked "asc" and appears to have no effect , the center switch opens, closes, and goes to vent position, and the third closes the roof. The problem is that when the roof is closed, it does not appear to be closed tight. While driving, it gets pulled open about 1/2" by the wind flow passing over it. So its constantly bouncing up and down while driving. Is this normal for this roof?
Blakoak