5DII refuses to focus in portrait postion

Phil1 wrote:

Intermittently my 5Dii refuses to focus when in the portrait position. It works in landscape and also when I turn the camera up the other way in the portrait position. When it happens, if I focus in the landscape mode and then revert to portrait, sometimes the focussing works for a while. It’s all a bit of a mystery!

Could I ask if anyone else has experienced this or if anyone can offer advice on the possible cause & cure?

The cameras is just out of its approval period so any advice you can give would be greatly appreciated as I’d like to think the dealer will sort it out even so but any 'ammunition' would be very useful.

Many thanks

Phil