I am trying to save anti-spam changes in parameters. eg.I set "Enable reCaptcha on registration form" to "yes". Then I click "save" and it has been changed back to "no". Same happens when I enter the "StopForumSpam.com API key". It clears the field when i click save.

Please help. My site has been attacked by spam bot and I need to sort this out ASAP! :)

PHP Version 5.3.27
Joomla! Version Joomla! 3.2.0 Stable [ Ember ] 6-November-2013 14:00 GMT
K2 Version 2.6.7
Site caneva.com.au/

You need to update your K2 to the SVN version 2.6.8. You can download it here: getk2.org/assets/get/