K2 Header Tabs Mystery!

Intending to replace them with graphics, I wanted to wrap -span- tags around the text in the -li- tags in the header.php file in K2’s theme directory.
But after trying various placements I noticed no change in the resulting page. After some more experimentation I found that I can delete line 135 from K2’s header.php file altogether and the pages still render just fine.
Can anyone tell me what I’m missing?
Here are the lines from the file; the specific line starts with <li class=”<?php if…

<ul class="menu">
			<?php if ('page' != get_option('show_on_front')) { ?>
			<li class="<?php if ( is_home() or is_archive() or is_single() or is_paged() or is_search() or (function_exists('is_tag') and is_tag()) ) { ?>current_page_item<?php } else { ?>page_item<?php } ?>"><a href="<?php echo get_settings('home'); ?>/" title="<?php echo get_option('k2blogornoblog'); ?>"><?php echo get_option('k2blogornoblog'); ?></a></li>
			<?php } ?>
			<?php list_pages_bugfix('sort_column=menu_order&depth=1&title_li='); ?>
			<?php wp_register('<li class="admintab">','</li>'); ?>
		</ul>