I've never liked the factory ejection on the Rossi 92. The Ejector spring is much too stiff, and on mine at least the ejector was so roughed and poorly ground that it needed every ounce of it to eject properly.
Took about an hour and a half with stones, files, sandpaper wrapped around drill bits, lots of steel wool, and quite a few different grades of polish to make it fit right, and mirror smooth.
Once it did, the rifle would ping shells off the corrugate roof above the shooting benches. This site:
http://stevesgunz.com/ has a much softer ejector spring. Well worth buying.
As to what happened to yours? I can almost guarantee (keep in mind I haven't had mine apart in about a year) that your ejector spring slipped off the shelf it sits on resulting in loss of ejection. I had that happen one of the many (infuriating) times I've had mine apart while cleaning up the action.
Probably a good idea to send it in, out of all of my collection I hate taking the Rossi apart the most. It always results in pinches, blood blisters, deep cuts, and a lot a swearing no matter how careful I am with it.
The actions need a lot of work from the factory imo. Or at least mine did. Now that I've got every camming, sliding, and mating sufaces mirror smooth, the ejector spring, and a 19lb Ruger Blackhawk hammer spring I can work the action on mine with the fingernail of my little finger with relative ease. So they are capable of being very smooth, and very reliable. They just don't come like that out of the box.
Much smoother than my Marlin 1895 actually. Though when I first bought them I thought the Marlin much smoother.