Here's a little something I read tonight that lot a lightbulb over my head. See what you think:
"Either sunken or floating, your flies are most apt to be taken while sitting, between pulls. Start and stop retrieves are effective for both bluegills and bass.
Another thing to remember is, if you have a hit on a floating lure and miss, return it quickly to the same spot.
Big bluegills (and sometimes bass) can't stand to see something that seems alive, sitting motionless above them. It irritates them no end. Even if they aren't hungry, eventually they rise and slash at it with their back fins.
If it is returned to the same spot immediately they will do this again. Keep returning it and they become enraged enough to take fairly and hook themselves."
This explains a lot of the false takes that are common when fishing surface flies, don't you think?