When both php4 and php5 are installed (and php5 is the default pointed to by /usr/bin/php), pptpconfig will fail because of php_gtk.so being a php4 extension. To avoid this error, the header of /usr/bin/pptpconfig.php should be changed from #!/usr/bin/php -q to #!/usr/lib/php4/bin/php -q I think quite a lot of users may have both phps installed by this stage, so this would be a valuable clarification.
Fixed in -r1.
