[Mediawiki-l] PHP Warning Problem since upgrading to 1.13 RC1

[The Gadget Doctor]

I'm wondering if anyone else has this. It took me a few days to spot this as
I forgot to check my error logs but now I see I've had 16meg of errors over
a weekend on a development site that gets very little traffic.
Since upgrading (with svn) my logs are full of:

[Fri Aug 01 12:38:01 2008] [error] [client 67.90.55.2] PHP Warning:
 preg_match() [<a href='function.preg-match'>function.preg-match</a>]:
Compilation failed: PCRE does not support \\L, \\l, \\N, \\P, \\p, \\U, \\u,
or \\X at offset 3 in /var/www/vhosts/
adv01.mysite.com/httpdocs/w/includes/Linker.php on line 1364, referer:
http://adv01.mysite.com/w/index.php?title=Fitzgerald:_Second-class_citizens%3F_-_December_16%2C_2007_by_Hugh_Fitzgerald&action=edit

Problem?