Thread:Extension talk:InviteSignup/Call to undefined method SpecialInviteSignup::getPageTitle

I work with:

MediaWiki	1.22.4 PHP	5.3.28-pl3-gentoo (uwsgi) MySQL	5.1.70

and I use last version of InviteSignup, fetched with git. I get this error:

[539c326f] /index.php/Special:InviteSignup Exception from line 376 of /var/www/wiki/htdocs/includes/SpecialPage.php: Call to undefined method SpecialInviteSignup::getPageTitle Backtrace:
 * 1) 0 /var/www/wiki/htdocs/extensions/InviteSignup/SpecialInviteSignup.php(136): SpecialPage->__call(string, array)
 * 2) 1 /var/www/wiki/htdocs/extensions/InviteSignup/SpecialInviteSignup.php(136): SpecialInviteSignup->getPageTitle
 * 3) 2 /var/www/wiki/htdocs/extensions/InviteSignup/SpecialInviteSignup.php(82): SpecialInviteSignup->getAddRow
 * 4) 3 /var/www/wiki/htdocs/includes/SpecialPage.php(631): SpecialInviteSignup->execute(NULL)
 * 5) 4 /var/www/wiki/htdocs/includes/SpecialPageFactory.php(488): SpecialPage->run(NULL)
 * 6) 5 /var/www/wiki/htdocs/includes/Wiki.php(298): SpecialPageFactory::executePath(Title, RequestContext)
 * 7) 6 /var/www/wiki/htdocs/includes/Wiki.php(602): MediaWiki->performRequest
 * 8) 7 /var/www/wiki/htdocs/includes/Wiki.php(467): MediaWiki->main
 * 9) 8 /var/www/wiki/htdocs/index.php(49): MediaWiki->run
 * 10) 9 {main}

What you can advise me?