Hi and thank you for the great plugin,
Today I updated to the new release and discovered a small error in the code that prevents XHTML Validiation.
In line 159 of the sidebar-login.php:
echo '<li class="page_item"><a href="'.wp_logout_url($redirect).'&redirect_to='.$redir.'">'.$thelogout.'</a>';
The addition of "amp;" after the "&" removes the error.
Best Regards