It may be your track is off.
I check tracking by rolling into a left turn (maybe 30º) and looking at the blades at about the 1'30 position on the tip path. A left turn puts the blades against the sky making it easier to see the tips. If you can see two distinct tip paths, they're off. For some reason I can see it better when in a turn than straight & level.
When tracking mine, I start adjusting until smooth, then go past smooth till it starts shaking again, and then back to smooth again.
IIRC, the SportRotors have pitch adjustment on each blade. It's possible that the undersling may be off if you have too little or too much pitch. More pitch = slower RRPM & more coning, and opposite for less pitch. Improper undersling will cause a two-per-rev vibration too, but I tend to feel that in the stick more than the frame.
Call SportCopter and see what they recommend for RRPM.
I'm sure others have different methods, but this seems to work for me.