OK, a few times I have noticed this, and its annoying so thought I would ask what I have missed. I have Single Autofocus selected, and the centre focus point selected. Normally shoot with centre area priority. So, I focus on something, it gets focus, but then a white box shoots off somewhere else and focuses there instead. Any ideas what this could be? What do I need to turn off, because this missed me quite a few shots this weekend….especially when I was trying to prefocus on a point only to have it wander off and focus on a wall or something.