Did you try moving the toe strap into the slot furthest from the toe? It need to be at an angle to cap over the boot.
Or you could just add this:
Burton Gettagrip Capstrap from Dogfunk.com
It's better than any cap you'll find.
Yes strap is at the slot furthest from the toe and is set up so that the cap is at angle over the boot. Won't stay put.
Not gonna spend another $40 to fix something that should work out of the box. Time to go a different direction.