Truenorth,
May I also suggest that the sure way to find out if your aircraft is in "balance" is by levelling the wings and observing to see if there is any yaw, ie change of heading.
If the aircraft is yawing at all with the wings level it is unbalanced. Note that this may be very subtle and gradual.
If the balance indicator doesn't agree, it's the one that's at fault. Probably not mounted in the panel correctly.
Another thing to look for is the airspeed with the ball in the centre, and the speed with the wings level with no yaw. The higher airspeed (in smooth air,with power constant) will indicate least drag.
This method takes a lot longer than just looking at the ball, but if you get used to it you don't need to scan to the ball at all while looking out. It also develops an insight into balance that you can't get from watching the balance ball.
By the way, what is it that is in balance during balanced flight? I'd be interested to see what you ladies and gents think.
Regards to all..