From the "duh" department:
When I set up my style switcher (changing text size, font and color) for this site, I mistakenly set the cookie value to menga.net instead of just menga.net. Why I did that I have no idea. Anyone who was coming here without the www found that the style switching didn't work. Ooooops.
Some of you may have to empty out your browser cache/cookies. I don't think that's necessary.. but I dunno. Better safe than sorry. Works in my firefox and IE now so it should work for everyone else.