error message, but it doesn't seem to affect much:

I'm getting the following error message displayed at the top of the site I've just started working on ( www.platosys.co.uk/platopress/ ):

Warning: preg_match_all() [function.preg-match-all]: Compilation failed: unrecognized character after (?< at offset 3 in /websites/123reg/LinuxPackage21/pl/at/os/platosys.co.uk/public_html/platopress/templates/hot_leafs/js/browser.php on line 56

I can still work on the site, and so far it doesn't seem to have affected anything, but it's constantly displayed. Any ideas what it might mean and how I can get rid of it?

Thanks,
Curtis

H,
open templates/hot_leafs/js/browser.php

on line 55, you will see this:
')[/ ]+(?<version>[0-9.|a-zA-Z.]*)#';

change it like this:

'\\)[/ ]+(?<version>[0-9.|a-zA-Z.]*)#';

I've tried that, but it throws up another warning message:
Warning: preg_match_all() [function.preg-match-all]: Compilation failed: unrecognized character after (?< at offset 3 in /websites/123reg/LinuxPackage21/pl/at/os/platosys.co.uk/public_html/platopress/templates/hot_leafs/js/browser.php on line 56

Should the solution you provided for line 55 start with \\ or //
Thanks,
Curtis

no, try one \ :
'\)[/ ]+(?<version>[0-9.|a-zA-Z.]*)#';