Well not really a bug, but more of an unintended consequence. I was trying to see why someone quoting my image ended up posting a bad link (see here). I think what's happening is that since my username is all uppercase, if someone quotes me and there is no normal text (i.e. just the image and a smilie), the shout protection kicks in and converts the whole post to lowercase... even links, which can be case sensitive. Anyways.. it doesn't really matter, just thought I'd report it.