Sounds weird, but yes, I think a piece is missing or something.

I have a Centaur triple 9s. When I was out riding yesterday, I shifted into my granny gear and heard a "thunk!" I looked down to see that my cage had come off of the derailleur assembly. Yikes. I slip it back on and head home, making sure to stay in my middle gear.

If you look at the image below, it's the two prong-y things below the limit screws marked FD-RE201 are where it's falling off of.

Taking a closer look, I tried fiddling around with the cable tension and limit screws, but I think there's something going on - basically, if I give it a tug, the cage comes off relatively easily if I'm in the granny gear. I can't tell if the washer-looking part labeled FD-RE107 is actually on there, but I'm guessing the cage isn't supposed to actually be moving around on the prong things.

Any input? I want to make sure I'm not crazy before hauling it into my LBS and have them look at me like I have 3 heads.