A couple of thoughts after reading this a few times. Your ball position may be too far forward, causing you to catch it a tad on the up. If the ball is forward of center for those pesky shots, you might try moving it back to center and see what happens. This ties in to the fat shots you were hitting, which could also mean you are swaying a bit going back or taking too long a backswing and decelerating through the ball. Pay attention to your back knee and keep it kicked in toward the target a bit; this will fix both possibilities.