D/A FD adjustment adjusting
 

I've got a Dura Ace brifter mated with a 600 FD, and I'm having a nitpicky problem. It's really hard to get the shifter to do the one click tweak adjustment. Shifting is no problem, but it seems like it takes too much force to do the one click, and I end up dropping to the small ring, which is very bad when I'm really cranking.

Is there something I can oil/adjust to make that tweak easier to do?