This thread is likely to get moved, but here goes. Naxo21s are not tele bindings. Tele bindings and AT bindings are not mounted in the same locations or using the same principles.
First level advice: Have a competent shop with jigs and experience mount the bindings for you. Take beer.
Second level advice: Mount AT bindings using the manufacturer's directions, or putting the boot midpoint over the corresponding mark on the ski Most skis have a boot midpoint mark on them, but I can't recall right now if the Crossbow does - anyone remember? If there isn't a boot midpoint mark on the Xbows, it gets a little more interesting. Beer helps here too.
Basic advice: With all things AT, consult Lou:http://www.wildsnow.com/articles/nax...o_mount_1.html
Key concept: AT (Naxo) bindings are not
tele bindings and should not be mounted the same way.