Fatal error: Access level to Piwik_SearchEnginePosition_Filter_AddAveragePage::filter() must be public

I am getting the following error when expanding the items in “Best search engines with average page”:

PHP Fatal error: Access level to Piwik_SearchEnginePosition_Filter_AddAveragePage::filter() must be public (as in class Piwik_DataTable_Filter) in /var/www/plugins/SearchEnginePosition/Filter/AddAveragePage.php on line 35

I am using Piwik SVN trunk r6460.

Also, the declaration must be compatible with that of Piwik_DataTable_Filter::filter().

I’m fraid this plugin is not supported. but please post the report in the ticket of the plugin directly maybe someone will help