[Alex_]

Sure?
I don't see the according code... it's just a simple str_replace, isn't it?
When I restricted it to one user only this one could view the history but the link showed up for others as wellg giving them always the same version on every number...

My code looks now like

if ( $vbulletin->userinfo['usergroupid'] == 6 ) {

$vbulletin->templatecache['postbit'] =  str_replace( $insert_point,  $insert_point . $new_text , $vbulletin->templatecache['postbit'] );

$vbulletin->templatecache['postbit_legacy'] =  str_replace( $insert_point,  $insert_point . $new_text , $vbulletin->templatecache['postbit_legacy'] );

$vbulletin->templatecache['postbit'] =  str_replace( $insert_point2,  $insert_point2 . $new_text , $vbulletin->templatecache['postbit'] );

$vbulletin->templatecache['postbit_legacy'] =  str_replace( $insert_point2,  $insert_point2 . $new_text , $vbulletin->templatecache['postbit_legacy'] );
}