Why the FK does FK look like this on linux?

http://www.29er.no/ihoss/images/flashkit.jpg

any ideas?

Does it look like that in Konqueror? Try changing the font size in your view settings. It could be that it appears normal for other sites because they set the font size.

Every other site looks normal. Flashkit also sets the font size, according to it's css. Haven't tried in Konqueror yet.

Just checked in Ubuntu, I got similar results only a bit less big-ish.
This is just a guess but I'm gonna say that a lot of the fonts on FK are probably MS fonts.
Fix: Download a windows font pack for your Linux OS, I saw one the other day I'll try and find it for you, if that doesn't work then it's probably going to have to come down to changing the font size like Genesis suggested.
Then again could just be Firefox getting confused with the CSS.