Maybe the problem is that you enter the style creator after changing the volumes
You have to enter the style creator first and than you can change the volumes of the tracks you want to change.
Than start the style creator with recording drum 1 or drum 2.
After recording something(or nothing)to these tracks you have to save the style as a userstyle and everything should be as you
wanted.
This works on my Tyros3 and I hope it will work again on the Tyros4 which I ordered.