Well the sommaire menu has no text css menu apparently. I just search around through the installation and saw nothing... But the thing is, it's not just the sommaire menu. It has something to do with the Forum theme. I say this because, look on your own site: http://www.areamike.com/index.php?t=17

Look at the very bottom where it says copyright phpnuke, etc. See the text size, then click on the forums in that site, and then look down at the bottom, and you will notice that gets small also.