Is õ actually the lower-case version of Õ (just like o is the lower-case version of O)?
One common problem with unicode and the likes is that some letters are not the same when lower-cased; mostly the
turkish I is mentioned (with ı <-> I and i <-> İ).
Although, it's entirely possible that the code points actually work as upper/lower-case for those two, and I'm as wrong as mIRC here

Edit: oh, nvm, just tried it with the Ä on my keyboard, and it's actually not considered equal.
Edit2: Apparently the forum software doesn't like those characters either; the İ turns into İ when I edit again)