Power clean-hip extension problem

[huskers1998]

When I do power cleans I jump and leave the ground and I also do make contact with my quads with the bar. But I didn't notice until someone else mentioned it to me. I am not pushing my hips forward all the way. the bar is hitting my quads but the crease of my hip is still a few inches behind where the bar is. If I do the movement slowly without the bar I can do all the motions and get my hips through. Its putting it all together that is causing me problems. Any cues or advice for this sort of issue? Thanks in advance.

[Mark Rippetoe]

Video?