Regular Expression differences between 4.4 and 5.2

Hi everybody, I'm trying to migrate our PHP code base to PHP5. For the most part the transition hs been smooth however I'm really stuck on a regular expression which gives different results in 4.4 and 5.2. I've looked through migration guides but as far as I can see nothing should have changed in Regex handling between the versions. I've created the following script below to test the match: <?php include( 'input.inc' ); $pattern = "/<!T_([^> ]+)([^>]*)>(.*?)<!T_end\\1>|<!T_([^> ]+)([^>]*)>/si"; preg_match_all( $pattern, $string, $matches ); echo phpversion(); var_dump($matches); ?> Input.inc contains the string that is giving the different results - its probably to long to include so you can find it at http://www.workingweb.nl/example/input.inc. The results of this being run can be seen at: PHP4 (desired result) - http://www.workingweb.nl/example/php4results PHP5 - http://www.workingweb.nl/example/php5results If the pattern modifier 's' is removed the regex behaves consistently again (but this breaks other pages on our website so can't be used as a workaround). Besides I don't see why that should make any difference. Here is the version information from the PHP CLI versions I've been testing with: user@debian:~$ php4 -v PHP 4.4.4-8+etch6 (cli) (built: May 16 2008 15:59:34) Copyright (c) 1997-2006 The PHP Group Zend Engine v1.3.0, Copyright (c) 1998-2004 Zend Technologies user@debian:~$ php5 -v PHP 5.2.0-8+etch11 (cli) (built: May 10 2008 10:46:24) Copyright (c) 1997-2006 The PHP Group Zend Engine v2.2.0, Copyright (c) 1998-2006 Zend Technologies Any help on this would be very appreciated. Thanks, Ewen