MLVI4 only on the card ???

[much]

I recorded some important RAW files into CF card (lexar 32gb 1000x) with my 5d mk2. I had problem on set allready, cause the card was not usable inside camera. When i put it inside the camera nothing happen... So i went home put the card inside the reader (Lexar USB 3.0 CF and SD car reader) and get this strange file "MLVI4" i don't have anything else on the card... what to do?