You might want to move your cleats back a bit and lower the saddle a couple millimeters to compensate. You might be riding toes-down to because the saddle is too high, to shorten the force arm of your foot, to stabilize your heel, or a combination of the above. Also, check the cleat angle. I've found that riding pigeon-toed (toes pointing inward) can strain the outside of the foot, ankle, and calf and inhibit the flexibility to drop the heel.