broken tilt shoe

The hook on the tilt shoe that holds down the spring loaded balancer has broken on multiple windows in our home. Once it snaps, it shoots the balancer straight through the window casing. This happens when they are closed, locked, and no one is touching/near them.
Is this something that could be covered under a warranty? If so, how do we find out who installed the windows/who the manufacturer is? The only id I can find (no etchings or serials) is the little white sticker.
Our home is 9 years old, we are the 3rd owners.

If not under warranty, is there a way to repair the shoe, tilt locks, and window casing?