10.6.5 update broke my PHP

The recent update stopped Limesurvey displaying security images on our Xserver. The error was: PHP Fatal Error: Call to undefined function image TTFText() on surveys/verification on line 116. I am posting here to ask if anyone can post the changes in 10.6.5 which might have done this. I have restarted in 10.6.4 and it works. Thanks.