Cyrillic messages in RSS are cutted off. Why?

Concerning RSS in cyrillic languages (Ukrainian, Russian, Belarus, Bulgarian, Serbian etc.) Why messages are cutted off at the half? Or sometimes are empty... This problem does impossible to use sites such as FriendFeed or desk-top clients as Twhirl for cyrillic users on Identica. It's very inconvenient. I use Ukrainian and I face it constantly. Thank you for help and sorry for my bad English. P.S. Atom is O.K.