RE: K9 antitwist in Aero 117 - advice needed
There are supposed to be slots in the board for the K9 washers to fit in. These slots run between adjacent strap holes. Preferably, you first put the K9 in place and then put the strap above it and mount the screw.
On my own (early) versions of 06 boards, there were no slots on the boards (the system was not tested enough for it to appear on the very first batch of boards). You might have such an early board and if so, just dont use the K9 washers.