Internal error

Detected bug in an extension! Hook SRUquery has invalid call signature; Parameter 1 to SRUquery() expected to be a reference, value given

Backtrace:

#0 /home/earthwid/www/www/w/includes/specials/SpecialListusers.php(115): wfRunHooks('SpecialListuser...', Array)
#1 /home/earthwid/www/www/w/includes/Pager.php(264): UsersPager->getQueryInfo()
#2 /home/earthwid/www/www/w/includes/Pager.php(156): IndexPager->reallyDoQuery('', 51, true)
#3 /home/earthwid/www/www/w/includes/specials/SpecialListusers.php(166): IndexPager->doQuery()
#4 /home/earthwid/www/www/w/includes/specials/SpecialListusers.php(278): UsersPager->getBody()
#5 [internal function]: wfSpecialListusers(NULL, Object(SpecialPage))
#6 /home/earthwid/www/www/w/includes/SpecialPage.php(851): call_user_func('wfSpecialListus...', NULL, Object(SpecialPage))
#7 /home/earthwid/www/www/w/includes/SpecialPage.php(578): SpecialPage->execute(NULL)
#8 /home/earthwid/www/www/w/includes/Wiki.php(251): SpecialPage::executePath(Object(Title))
#9 /home/earthwid/www/www/w/includes/Wiki.php(63): MediaWiki->handleSpecialCases(Object(Title), Object(OutputPage), Object(WebRequest))
#10 /home/earthwid/www/www/w/index.php(114): MediaWiki->performRequestForTitle(Object(Title), NULL, Object(OutputPage), Object(User), Object(WebRequest))
#11 {main}