Embed Font Futura Book

Question

Hi. I'm trying to embed the font Futura Book in my Flex application using css:

/* Futura Book */
@font-face {
    src:url("../fonts/futura.ttf");
    font-family: "Futura Book";
}

@font-face {
    src:url("../fonts/futurab.ttf");
    font-family: "Futura Book";
    font-weight: bold; 
}

@font-face {
    src:url("../fonts/futurabi.ttf");
    font-name: "Futura Book";
    font-family: "Futura Book";
    font-weight: bold;
    font-style: italic;
}

@font-face {
    src:url("../fonts/futurai.ttf");
    font-family: "Futura Book";
    font-style: italic;
}

But for each one I get an errormessage:

exception during transcoding: Unexpected exception encountered while reading font file '[..]/../fonts/futura.ttf'

I've also embedded other fonts in the exact same way and they compile fine. Any suggestions?