Ok, I've got the same problem on the driver's door (93 se-r 2dr.) and took my door apart only to find the same as you guys, no provision for adjustment! So I ended up Lubbing the tracks and it was better, but still obviously moving away from the b-piller, and then buttoned it all back up.
A couple of day's later I was looking in my factory service manual (yes I'm lucky enough to have gotten one) and what they say to do is to actually flex that runner in the middle forward or backward to make the adjustment.
See I did the same as you, and was looking to loosen those center bolts, but realized they made no provisional slotting for that!? So I haven't taken the thing apart since I read that, but the first guy who does, let us know if that factory cheeze ball fix does it.
Another thing I was just thinking after watching that sissy track
"flex away" from the b-piller, would be to just fab up a little extra brace to help give it some back bone so to speak? I'm giving that a lot of though.