What I did is:
Go in the settings, make sure you put this way:
Edit the page.php in the template and put this
“<?php if ( function_exists( ‘the_last_modified_info’ ) ) { the_last_modified_info(); } ?>”
Then in the settings look for the HTML Template Tag, put this:
<p class=”post-modified-info”>This page is last updated on %post_modified%</p>
Put it in both “Post options” and “Template Tags” then save
Volia, no more showing ‘admin’
Hope that helps