Fatal error: Call to undefined function woocommerce_get_page_id() in..

Hi,
I’ve just updated the woocommerce plugin into latest version now this fatal error is everywhere!
Fatal error: Call to undefined function woocommerce_get_page_id() in [-directory path-]/wp-content/plugins/woocommerce/classes/class-wc-cache-helper.php on line 36
website url: http://annasclipinhairextensions.com/
What to do now?
Regards

http://wordpress.org/extend/plugins/woocommerce/