Are youo using the breath box that goes in the chin guard that came with the helmet? I was not using mine nor was I using the nose piece that came with the goggles and was having all kinds of problems fogging. Once I finally gave in and put everything in the way it is designed to work and used it as a "complete system"...to my amazement, my fogging problems went away! Now I love my 509 helmet/goggle combo and wouldn't trade it for anything!
Boone
is this the breath box you speak of?
http://www.firstplaceparts.com/509-HEL-EACC-BB.html