Disintegrated vent, Warning about using vent cushion/inserts

I have two vents. One in bath one in bedroom.
We only use the cushion in the bedroom and I had to replace both vent covers last year (2011 model).
They are just cheap.
Nothing to do with the cushion.

I discovered mine when I was recaulking. I could put my finger right through them. bought the thicker replacement from CW.