Looks like the top itself isn't folding all the way. Perhaps the window area isn't folding properly as its going down? Also, there are fairly deep "troughs" at either end of the package shelf. An item placed on the shelf can easily slide into one of the troughs out of view and impede the top in its last few inches of travel. Ask me how I know.
Since you have gone in to lube the joints i assume you would have caught that though. Just trying to think of the non-mechanical possibilities since I don't entirely know how these tops work.