OK, I seem to have found a better hook for the recursive parsing (as well as a competent newsreader), so we may be back in business. The new version seems to address these issues.
Thank you!
Had a quick third look at it, one small thing is that using this wiki input on a test page: ---------------------------------------- {{#lst:Main Page|/}} ----------------------------------------
Which when error_reporting(E_ALL); is included in LocalSettings.php, will cause these PHP warnings: ---------------------------------------- <br /> <b>Warning</b>: preg_match_all() [<a href='function.preg-match-all'>function.preg-match-all</a>]: Unknown modifier '' in <b>/var/www/hosts/mediawiki/extensions/lst/lst.php</b> on line <b>174</b><br /> <br /> <b>Warning</b>: Invalid argument supplied for foreach() in <b>/var/www/hosts/mediawiki/extensions/lst/lst.php</b> on line <b>176</b><br /> ----------------------------------------
Also managed to get an "Unknown modifier 'z'" on the same line, by doing "{{#lst:Main Page|/iz}}", but it's probably the same thing as the above.
Other than that, it's looking good.
All the best, Nick.