Don't overtighten the strap. The boot should freely slip in without the back plate getting hung up on the heel of the boot. You can get a tighter fit by increasing the back plate angle instead.
2008 LibTech Dark 157 with Union Force bindings (mod with Burton toe strap).
2010 Bataleon Green 161 with Rome Targa bindings.
2007 Palmer Pulse 162
2011 Ride Insano boots w/ redhot Superfeet insoles
Stance +15/-15 @ 24"