I was trying to avoid causing some kind of "crack-gate" lol. I had contacted another member who had a couple X-Stars via PM back in August when I first noticed this, what looked like a hair line crack in my rear right arm. It didn't move or look bad so we concluded to watch it and hope it was just in the finish of the shell. Well the other morning after a flight I notice it had vibration dust on it and it now seemed to move. Upon further inspection it is now a crack all the way through the lower shell half. This XSP has not been crashed or flown hard, actually not even flown that much. I am hoping this was just an isolated case of defect and not a sign of things to come for other users. This crack did not start at the screw hole, it was in the arm itself then moved toward the screw hole.
Just to be safe keep an eye on yours. These were not there when new and did develop over time and then failed. They are hard to see so look carefully.