[Mediawiki-l] Unrendered $input in extension

Hi, I'am writing some extensions an use usually a scheme like that:

<url src="http://www.destatis.de/basis/d/biwiku/hochtab1.php">/<!-- Content Begin -->(.*?)<!-- Content End -->/s</url>

I rely heavily on the fact that in my render function "renderUrl ($input, $params)" $input contains the unrendered code between <url>...</url>. But if I look to the content (after updating from 1.5.5 to 1.6.5) $input contains:

/UNIQ197a31dbac4f402-HTMLCommentStrip27fc8dec69226a9200000001(.*?)UNIQ197a31dbac4f402-HTMLCommentStrip27fc8dec69226a9200000002/s

instead of

/<!-- Content Begin -->(.*?)<!-- Content End -->/s

Obviously some rendering has been done. I remember I have seen somewhere (but where ?, can't find it anymore) how to access the unrendered text. Can someone help me ?

Thanks in advance

Sigbert