[Lynne]

Really? Strange, because I have something almost exactly like that in a plugin and it works just fine:

PHP Code:

$find = '<label for="select_daysprune">'; 
$add_before = '<label style="display:inline" for="uid">'.$vbphrase[userid].'</label>
and more stuff 
'; 

$vbulletin->templatecache['moderation_filter'] = str_replace($find,$add_before.$find,$vbulletin->templatecache['moderation_filter']); 


I wonder if it's because you didn't preregister your variable after you defined it.

PHP Code:

vB_Template::preRegister('FORUMHOME', array('thistemplater ' => $thistemplater )); 


And, I doubt you need this line:

PHP Code:

$templater->register_page_templates();