I had a file with an é or è in it that wouldn't complete before I changed the name.
Also, some non-critical bugs in the mac version is that the toolbar flickers when the Connect/Disconnect button is switching, and that the window at start is too big for my resolution, 1024x768, so I have to press the green button to make it fit.
Another thing is that if I copy in a ed2k link, and it's too long to fit in the ed2k link box, it isn't recognized as an ed2k link.