I think the raking will help. It could also be a "funny wheel." I bought a whole bunch of wheels, raked them all about the same, and loaded them up using pretty much the same method. One of them just doesn't want to take an even coating of compound. It feels stiffer than the other wheels, and I think it just might need some more raking or a lighter touch or something.

Anyway, I hope you figure out what's going on with your wheels.