As detailed in my lessons thread, I have been battling a shank for the last whole eight days. And guess what. It went away today. What worked for me is better tempo. I was trying to hit too hard and getting the clubhead into all sorts of bad positions. Slowing it down and practicing shorter swings for a while before going again for the full swing worked.
Man that happens to me sometimes, my pro suggested that I practice with a head cover under my left arm (I'm right handed) so that my take away is solid and close to my body giving me a connected feeling. What I used to do is separate my arms a lot which extended at impact leaving it close to the heel or shanks. Good luck