Shoutbox

I've had it for a while now - it won't let me show my display pictures? When I click on 'Allow Others To See My Display Picture' as soon as i click okay it goes back to unticked. Or when I click on browse it came up with "Cannont show Display Pictures. Please Pick another one" or something which I found strange.
Strange thing is though, I made another account and it let me use Display Pictures fine , so it's just on the account I usually use.
Has anyone had this problem, or does anyone know how I can solve it?

Thanks.