Update:
The problem with crossing division boundaries seems limited to IE 6. Firfox & IE 7 handle it just fine so I decided, for now, to edit the tpl_header so that if someone shows up browsing in IE 6, the logo will not be called. Eventually (next couple days) I'll make a smaller logo that won't cross the division just for IE 6. There will be a gap above the categories listing that won't be there in Firefox/IE 7 but oh well.
Code in tpl_header.php looks like this:
<?php
if (strpos($_SERVER['HTTP_USER_AGENT'], 'MSIE 6.0') == FALSE) {
?>
<div id="logo"><?php echo '<a href="' . HTTP_SERVER . DIR_WS_CATALOG . '">' . zen_image($template->get_template_dir(HEADER_LOGO_IMAGE, DIR_WS_TEMPLATE, $current_page_base,'images'). '/' . HEADER_LOGO_IMAGE, HEADER_ALT_TEXT) . '</a>'; ?></div>
<?php
}
?>
Using PHP, if HTTP_USER_AGENT (a string that describes what the requesting user is using as a browser) does not have MSIE 6.0 in the string, I'll display the logo. If the string does contain 'MSIE 6.0', the code that calls the logo gets skipped.
After I make the smaller logo, I'll toss in an ELSE statement that calls the smaller logo up for IE 6 users.