This just happened all of a sudden. When I insert a card, and push down, it just pops back up. I have tried different cards. I'm thinking there is some kind of mechanical failure. Has anyone else experienced this? I wonder if there is a simple fix Don't want to send it back to Nikon--the warranty has expired and the shipping cost and repair would be exorbitant. I can get along with just slot 1 for the immediate future.