Preg_replace() error.

We are having an issue having upgraded to 6.x-1.2 and have rolled back to fix the issues currently.

When creating a node we have an auto alias patern set up as follows [term-raw]/events/[nid]

However when the node is created we are getting urls created as follows /events0

It seems as the tokens are being removed. On further investigation we noticed the following error in the watchdog:

preg_replace() [function.preg-replace]: Unknown modifier '|' in /var/www/llasdev/htdocs/sites/default/modules/pathauto/pathauto.inc on line 206.

Line 206 in pathauto.inc is $output = preg_replace("/$seppattern\/|\/$seppattern/", "/", $output);

This is a new edition to the code for version 6.X-1.2. If I comment out the line the alias's are created correctly.

PHP is obviously having an issue with the | modifier in the preg_replace() pattern. I don't know enough about regular expressions to see why that wouldn't work so any suggestions would be gratefully recieved.