I have made a poll and got an HTTP Error 500. In Apache log is stated, that: [Sun Oct 13 14:42:04 2013] [error] [client 192.168.56.7] PHP Fatal error: Call to undefined method JApplicationHelper::getHash() in /vhosts/polls3.home/components/com_communitypolls/models/polls.php on line 1985. What should I do now?

FYI: Joomla! 2.5.14 / Community Polls 3.4.1