Perhaps in an effort to keep your shadow from moving... you don't get to your right side in the backswing? I hate hitting from a shadow too, but I don't notice too much difference really.
My Shadow - Page 2
TheSandTrap.com Top Picks
I just came from the range to see if I find a solution here. However my problem is totally opposite. Hit the ball 100% better when I can see my shadow; I don't have to even look at the ball. I just look @ my shadow because I can see my swing specially when I'm backswinging. I can see my club well set at the top. Then in the downswing, by looking at it in my shadow it helps me make a nice round dropdown that prevent me coming over the top. When I have no shadow it gets very difficult for me to hit long irons all the way down to my driver. I also swing very well when I can see myself on the mirror. So what I do is practice @ the range @ night so I can select a slip that the light comes from the front ( to overcome my problem). When my swing goes south I jump to a slip that the light comes from behind. I take like five swings repeatedly looking at my shadow then I close my eyes and take a couple more to imprint the feeling of a good swing. Perhaps you should do the opposite.