Thread:Extension talk:Zend Search Lucene for MediaWiki/Undefined Method User::getOptions()

When I try to open "Special Pages" I get an error:

Fatal error: Call to undefined method User::getOptions in /users/lenjo/www/mediawiki-1.15.1/extensions/PslZendSearchLucene/PslZendSearchLucene_body.php on line 116

Where is the method defined? How can I fix that?

Edit: I found the class where getOptions is defined. But that does not solve the problem...