and found some "rough spots" on the guide rails, as was suggested.
There is a rounded edge on the roof edges of the rear roof half that can work like a battering ram on the front roof rails when the roof is disengaged to lower it.
Guess I should have taken some pics, but I will briefly explain my novice findings.
When you lift to disengage the roof for lowering, if you do not hold up the forward half(where the lift handle is), then the rear half proceeds to lower first, under the forward half and then hit the front roof rails. Problem is that if the forward half is also lowering somewhat, then the battering rams of the rear half impact the forward half rails hard enough to roughen it up.
1. Make a sanding block about 1" wide and sand the rough spots as smooth as you can get them.
2. Oil the rails. I used some motor oil on a small rag. Oil the battering rams.
3. To prevent any future battering of the rails, when you lift up the disengage handle to lower the roof, hold up that half for a couple of seconds until you see the rear half fall to where the battering rams will not hit the forward roof half rails. Then let the front half lower with everything.
Some white tough-up paint can be included prior to lubing.
It's working(raising) much better now.
I noticed a piece of hard white plastic tape on one of the rails, indicating that somebody might have put that there to cover up a "rough spot". Hmmmmm...