I have this problem and it can be all or any of the following problems:
Hitting down on the ball (makes it pop up)
Overswinging
Casting
Teeing the ball to high
Left Wrist bent at impact
Scooping the ball up with the wrist
If you look at all these possiblilities you will be cured!
I know that some fairly simular and are all inter related.
Some one also said teeing the ball too low. This can happen as you are hitting down on the ball but seriously teeing it lower should help whatever all your problems are it did for me
