You can’t just “fix” it. wp_register contains the
<li>
bit you are referring to. I couldn’t actually find the function to modify it so I wrote my own. This should do it for you. I had to create a custom one to insert a <span> section right around the text.
function custom_regadmin() {
global $user_ID;
get_currentuserinfo();
if ('' == $user_ID) :
$link = '<a href="' . get_option('siteurl') . '/wp-register.php">' . __('Register') . '</a>';
else :
$link = '<a href="' . get_option('siteurl') . '/wp-admin">' . __('Site Admin') . '</a>';
endif;
echo apply_filters('regadmin', $link);
}
Call custom_regadmin() instead of wp_register() to use this one. If you need a place to put the code then put it in your theme’s function.php file. It will work fine from there. ??