Anyone ever had problems with Richmond gears?

I had a set installed in my car yesterday, and they whined so badly that the mechanic took the cover off again to double check his setup.
He found nothing wrong with the install, and the contact patch on the gear is dead center, he's convinced the gears are defective,
and told me to send them back and exchange them for a new set.

I'm beggining to think someone is trying to tell me something, this is the second time we've opened that case and could not finish the job.

John