I've been trying for some time to figure out if I'm doing something stupid, but I can't find anything wrong that I'm doing or have set.
When shooting with available light, my 5D2 consistently needs +2/3 to +1 EC for the shot to come out looking roughly right. In fact when I shoot at +2/3, I often need to boost exposure in PP, so it's probably fair to say that it needs +1 EC all the time.
Does this ring a bell with anyone? Should I send the thing in to Canon yet again?