Re: Navigation Font issue...
Among other things, your @font-face points to "css\avgr_reg.ttf" -- note the backslash. And IE (the browser most likely to love backslashes in a path) requires EOT fonts for web embedding. To get a full set of web-embeddable versions of your font, go to Font Squirrel -- feed it a TTF font, and it will return the font modified for EOT and WOFF (the next-generation standard) along with a cross-browser @font-face entry.
“Beware of bugs in the above code; I have only proved it correct, not tried it.” --Donald Knuth
"It was as if its architects were given a perfectly good hammer and gleefully replied, 'neat! With this hammer, we can build a tool that can pound in nails.'" -- Alex Papadimoulis (on TheDailyWTF.com)