Yeah... don't click the bottom of your buttons (I'm kidding ~smile~) or, if I wanted to be an extra smartalec I'd say learn to use keybinds ~evil grin~
That said and all teasing aside, I would say just modify the position of the button a little so it doesn't overlap with the buttons you're trying to mouse-click. Just edit this line and change the highlighted values (blue to move it left/right or purple to move it up/down)
Code:
MiniMapBattlefieldFrame:SetPoint( "BOTTOMRIGHT", MiniMapWorldMapButton, "TOPLEFT", 2, -12 );