Extension talk:ListSubPages

Caching issue
This is a good extension, but it does not seem to work except the first time a page is saved (or any subsequent times it is saved). My guess is that it is a caching issue, but I don't know how to solve it.

Does not work with PHP 5.3?
I use Mediawiki 1.15.4 on FreeBSD, Apache 2.2.16 and PHP 5.3.3. The plugin seems not to work (although it did on Mediawiki 1.14.1). I get this error in httpd-error.log: [error] PHP Warning: Parameter 3 to ListSubPages_render expected to be a reference, value given in /usr/local/www/mediawiki/includes/parser/Parser.php on line 3243

Any ideas what's wrong?