Are we meeting at the range this evening? You just described my swing and my misses perfectly!
For me, this is caused by a pull compensation that I'm getting rid of. This thread has some good info
http://www.lynnblakegolf.com/forum/viewtopic.php?t=674. I like Brian's message where he states "The club should enter the ball at 4 o'clock but EXIT at 8:00!". My swing was entering at 4 and leaving at 10, and when I make it exit at 8 it forces me to get my plane up where it should be.
I'm very interested in other's responses.