Stereo & Electronics - Problem with head unit...

I isntalled a after market HU a couple weeks ago and everything was fine. Well the other day, I got on it pretty hard and the whole damn unit came out. It was crazy. It wont seem to go back in. Could it be that the bolts just came undone or what? Has this ever happened to anyone else?

Questions:
* How was it installed?
* Did you use the "sleeve" that the headunit is supposed to snap into?
--The "sleeve" should have come with the headunit and is first attached to the mounting bracket by bending its tabs. Then the headunit is slid into it until it "clicks" in place.

If it fell out, then it wasn't properly installed or it somehow worked itself loose.

Well I bought it off of here and I went out and bought the antenna, wiring harness, and black mounting piece because thats what everyone said is all I need. I slid the HU in the adapter with the spacer and slid it into the dash. Then I screwed it down to the holes. Did I miss something?

When you slide the HU into the sleeve, you need to bend little tabs toward the front of the sleeve to make the headunit stay secure to the mounting kit .

Sounds like you just need to bend the tabs up so it doesnt move around.
They are easy to bend just use a flat tip and a pair of pliers

The sticky at the top has a video on how to get the h/u out