In addpost.php

search for:
Code
	// --------------------------------------
	// Now update some stuff in their profile


add before:

Code
if($Board != "boardkeyword1" && $Board != "boardkeyword2"){
   $UTotalposts = "U_Totalposts = U_Totalposts + 1,";
}



search for:
Code
SET    U_Totalposts = U_Totalposts + 1,

replace with:
Code
SET    $UTotalposts



boardkeyword1 and boardkeyword2 (add as many boards you want...) are obviously the board keywords of the boards you want to exlude from the count.