Fatal error: Class 'Z' not found

[ke_sheng_jie]

I am testing Zabbix 2.0.0rc3. I have it setup on a test server and have copied the frontends/php directory to my htdocs directory. Whenever I go to the Queues page in the Zabbix GUI, I am getting this error:
Fatal error: Class 'Z' not found in /usr/local/apache2/htdocs/include/config.inc.php on line 24

After I visit the Queue page, the error shows up on every page. Has anyone else run into this or is this a known issue? Any ideas how to fix it if it's just my machine?

[ke_sheng_jie]

Found out what was causing it

I had installed Alternative PHP Cache (APC) on the old version of Zabbix, but it's causing the above error with Zabbix 2.0. Now that I've removed it, everything works fine.