Open a new tab and type an address with some Russian characters, for example, http://ru.wikipedia.org/wiki/ЧС7 , then press Enter. The address will change to http://ru.wikipedru.wikipedia.org/wiki/%D0%A7%D0%A17 , and a typical "Server not found" page will appear, instead of the correct page being opened. Maybe this is somehow related to the autocompletion feature.
Oh, if you copy the address from the above description, it won't work because Cyrillic characters will get replaced by "%D0%A7%D0%A17". You have to type the address to see this bug.
Indeed. this should be fixed in F16 though. See duplicate.