Looking at Firefox's Web Console I see the following CSS errors (amongst others):
background:#fff, estilos.css:32
downloadable font: table 'cmap': failed to parse table (font-family: "arialNarrow" style:normal weight:bold stretch:normal src index:0)
source: http://www.meengoo.com/test/fonts/ArialNarrowBold.ttf estilos.css
downloadable font: rejected by sanitizer (font-family: "arialNarrow" style:normal weight:bold stretch:normal src index:0)
source: http://www.meengoo.com/test/fonts/ArialNarrowBold.ttf estilos.css
The cmap errors mean that the font is corrupt. You are probably best to use a service like http://www.font2web.com/ to fix the font and convert it to appropriate formats. It also creates CSS that you could then tweak to give you the correct bold and italic rules.
You are correct that font-family does not need a unique name when you are defining @font-face rules (in fact, when defining font variants it shouldn't). The only problem I can see is that you have some extra font-weight and font-style rules.
Try this:
@font-face{
font-family: arialNarrow;
src: url(../fonts/ArialNarrow.ttf);
}
@font-face{
font-family: arialNarrow;
src: url(../fonts/ArialNarrowBold.ttf);
font-weight:bold;
}
@font-face{
font-family: arialNarrow;
src: url(../fonts/ArialNarrowItalic.ttf);
font-style:italic;
}
@font-face{
font-family: arialNarrow;
src: url(../fonts/ArialNarrowBoldItalic.ttf);
font-weight:bold;
font-style:italic;
}
Note that the order is important, the bold/italic style must come last. Doubters should refer to http://www.metaltoad.com/blog/how-use-font-face-avoid-faux-italic-and-bold-browser-styles to see why it should be done this way.