Ah, thanks, mercime. That was the problem. I was wondering what that junk was when I initially put up those posts, but I forgot about it.
Thanks to all for your good ideas and quick responses.
Thanks for the link, jonimueller. I’ve seen conditional comments before, but I’ve never used them. I didn’t see a way to put conditional comments in the CSS directly, so I made a conditional statement in the header to redirect the CSS reference file to an IE-specific one I made.
<link rel="stylesheet" href="http://worldtreephotography.com/wordpress/wp-content/themes/default/style.css" type="text/css" media="screen" />
<!--[if IE]>
<link rel="stylesheet" href="http://worldtreephotography.com/wordpress/wp-content/themes/default/style-ie.css" type="text/css" media="screen" />
<![endif]-->
The file style-ie.css has no asterisk or inheritance tricks. It just has different values for the relevant widths (#page and .narrowcolumn).
Sadly, this does not seem to fix the problem. Any I doing it incorrectly? I’ve never used XHTML or PHP before, so I could easily have messed up.
Thanks again for your help!