1) Try putting an absolute link not relative link to your eot font - somehow old IE just don't know in which folder the css file is 2) make 2 extra @font-face declarations so it should look like this:
@font-face { /* for modern browsers and modern IE */
font-family: "Futura";
src: url("../fonts/Futura_Medium_BT.eot");
src: url("../fonts/Futura_Medium_BT.eot?#iefix") format("embedded-opentype"),
url( "../fonts/Futura_Medium_BT.ttf" ) format("truetype");
}
@font-face{ /* for old IE */
font-family: "Futura_IE";
src: url(/wp-content/themes/my-theme/fonts/Futura_Medium_BT.eot);
}
@font-face{ /* for old IE */
font-family: "Futura_IE2";
src:url(/wp-content/themes/my-theme/fonts/Futura_Medium_BT.eot?#iefix)
format("embedded-opentype");
}
.p{ font-family: "Futura", "Futura_IE", "Futura_IE2", Arial, sans-serif;
This is an example for wordpress template - absolute link should point from where your start index file is.