str_replace problem

[emath]

im trying to relpace a two rows in SHOWTHREAD template,

this is my code :

PHP Code:

if ( $vbulletin->options['active_users_onoff'] ) {
    $replace = '                        <!-- Refresh Button -->
                            <vb:if condition="$vbulletin->options[\'active_users_onoff\']">
                            <button onclick="showUsers()" type="button" style="float:left;"> {vb:rawphrase refresh_button} </button>
                            </vb:if>
                <div id="thread_active_users">' . PHP_EOL . '                <p>' ;
    vB_Template::preRegister('SHOWTHREAD',array('replace' => $replace));
    $vbulletin->templatecache['SHOWTHREAD'] = str_replace('<div>' . PHP_EOL . '                <p>', '\'' . $replace . '\'' ,$vbulletin->templatecache['SHOWTHREAD']); 
} 


in the template, there is a <div>, new line, some space and <p> . this is what i would like to change... but the above hook doesnt work ( placed in showthread_complete )

Edit : tried also with "\n" instead of PHP_EOL with no success .


thanks