K200D focus adjust hack - AF area??

I've been playing about recently with the focus adjustment hack on the K200D, since my new DAL 35mm lens was focusing consistently incorrectly. I've fixed it with a +60 adjustment, but because it's a hack, that adjustment applied to all lenses. I've tested my other lenses and they seem ok with it, the DA 35 ltd is a bit better than before, the infinity focus problem I had with it seems to have been resolved. The only loose cannon is the Tamron 17-50, which displays variable results with any focus setting, no surprises there.

The K200D doesn't have the most advanced or reliable AF system around anyway, so I'll always miss some shots.

When entering the debug menu option for AF adjustment in the K200D, there are two options to change. One is the adjustment amount, which is what I've done so far. The other is "AF Area Test", which has four settings: 1 - 4.

Does anyone know what these AF areas are? Do they indicate that different AF points can have their adjustment amount changed independantly? Or something else entirely?