my last idea
on the d300 menu A5 (activation AF) set "AF/on only"
i hope quite the same on d200
i used this process for example this afternoon in this jewel sequence
aperture mode + spot on function button, instant correction for adjust expo and AE-L, then AF-ON , and upside shoot button , that's simple now :
|Classic Cruisers by Surfwalker|
from Song Titles- Little Deuce Coupe
|Gosford Reflections DP by MarioSS|