It's possible that the ejector pin is broken.  One of my Norwegians has that problem, and it does lock up a bit sometimes.  I've not messed with it, some of the Norwegian pins are really locked in there!  The pin is broken, but you can't pull the ejector out.  It will sometimes go forward enough to stop forward movement of the bolt.  Despite that movement, still won't come out of there! Of course now that I said that, I picked it up and it's working just fine.  The rear of the ejector can bind where it pushes against the bolt to flip up too.