Thanks for thank NiteWave reminded me you'd have to enable the plugin for it to work so plugin active from 0 to 1 - see http://vbtechsupport.com/127/
so from
PHP Code:
<plugin active="0" executionorder="1">
<title>Send X-Accel-Expires header for logged in users</title>
<hookname>style_fetch</hookname>
<phpcode><![CDATA[// Do not cache logged in user pages
if ( $vbulletin->userinfo['userid'] )
{
header('X-Accel-Expires: 0');
};]]></phpcode>
</plugin>
to
PHP Code:
<plugin active="1" executionorder="1">
<title>Send X-Accel-Expires header for logged in users</title>
<hookname>style_fetch</hookname>
<phpcode><![CDATA[// Do not cache logged in user pages
if ( $vbulletin->userinfo['userid'] )
{
header('X-LiteSpeed-Cache-Control: no-cache' );
};]]></phpcode>
</plugin>