Quadruped Walk Cycle

http://www.youtube.com/watch?v=f1hSlKki3Cw

Here is a rotation and a video of a horse walk cycle I created. I realize that the head, shoulder, and buttocks controllers were messed up in the scene render, however the walk cycle remains the same.

I'm having some difficulty in getting the horse's feet to match the groud plane. I created a walk cycle and duplicated the keyframes for the leg controllers. I then keyframed the main horse controller in a forward motion at a variable rate. This does not seem to be the best way to go about achieving a lot of high quality cycled motion.

I have recreated the walk cycle many times, and although it seems to work out alright sometimes, other times it becomes way off. I've tried scaling keyframes in the curve editor to no avail.

Any ideas? I'm using max 8. I have a fair amount of footage to be made with the walk cycle and it would not be economical to key frame each of his feet to meet the ground plane exactly for every step. I know I can change around my camera shots and with no need to see his feet, but after spending a significant amount of time on skinning and the walk cycle that would be a shame.

Thanks ahead.