Put:
$wgUseTidy = true;
into your LocalSettings.php. That should fix it up.
Yup, that did the trick, Mike. I also had to add the .infobox class to my CSS. For some reason it wasn't there. That added the borders and the floating right.
Thanks too for the compliments on the site. The reason for its narrowness, is that I don't want (and readers really don't want) lines of text expanding indefinitely, so the width I hard coded it to is for optimum reading. Of course, others will disagree.
I've sort of come up with a style for all the Pynchon wikis (http://pynchonwiki.com/), and there's really nothing fancy. Just modifying the heck out of main.css and creating background images and "logos".
If anyone has any specific questions, I'd be glad to answer as best I can.
But thanks so much for that infobox fix!
Tim