I'm just going to through out some stuff to check.

Check your draw stop to make sure it's tight.

Have you checked your mod screws? One may be loose and it's hitting the limb.

Also, check to see if the cam itself could be making contact with the limb. Do you feel like the bow doesn't want to draw smoothly?Have someone watch you draw and watch the cam.

I haven't had more than about a 1/4 of a dot difference between my cams. Are both limbs screwed in the same distance?

Beyond that I'd recommend taking it to the pro shop and having them give it a once over.