Font-weight and font-style render randomly in IE8

Question

I am working with a template set and in IE8, the webfonts switch randomly between bold, italic, regular. I already saw this question: IE8 Renders font weights randomly, but as mentioned there and can also be seen below, I don't have more than 4 weights defined. Specifying a different name for each weight/style is not really an option.

I already made sure, the Content-Type of the fonts are correct, this did unfortunately not cause the problem. Any other ideas?

@font-face {
    font-family: 'Name of Font';
    src: url('../fonts/font-bold.eot');
    font-weight: 700;
    font-style: normal
}

@font-face {
    font-family: 'Name of Font';
    src: url('../fonts/font-italic.eot');
    font-weight: normal;
    font-style: italic
}

@font-face {
    font-family: 'Name of Font';
    src: url('../fonts/font-bolditalic.eot');
    font-weight: 700;
    font-style: italic
}

@font-face {
    font-family: 'Name of Font';
    src: url('../fonts/font-regular.eot');
    font-weight: normal;
    font-style: normal
}