I put in my new harmonic damper about a month ago and when I first installed it, the belt didn't get seated right, and the pulley wasn't square and made a noticable noise when I started the car.

Well I fixed the wobble and I just had to get a new belt because the old one got destroyed in the process.
Well like a week later I hear slapping coming from inside my engine bay and the new gatorback belt is ripping away at one side. I would say its down to 3/4 belt in some spots.
My question is how do you know for sure that you got your damper on square? I figure it needs a minor adjustment....but am surprised because it went right on no problems?

Ideas on how to fix/check this?

 

Check the alignment with the other pulleys. Sounds like it is off.

 

To further this, take a straight edge and lay it from the harmonic to the pulleys.