I was giong to open up the sunroof today because it was such a beatiful day only to find that it would not open. It will open to the vent position just fine (back of sunroof opens upward.) But the sunroof will not retract into the roof. It will go down about 1cm but it just stops and can't move. If you get out of the car and push down on the glass, it'll drop down and then go back into the roof. It does this everytime. It only seems to be sticking on one side though and it almost looks like the sunroof frame is bent. (maybe forced entry? But why do it through the sun roof? ). anyway, anybody know why the sunroof would be acting up like this? It worked fine before, but now it is sticking and won't go down into the roof like it used to. If you stand outside the car and watch it, you can see the whole roof flex from the sunroof catching on it.
btw, the sunroof in the riv appears to be teh same one as is used in the Bonneville so they're the same mechanically.

is it mounted on tracks check those to see if they are blocked

Lubed it lately?

The glass and track may need to be sychronized or you may have a broken gear.