this can be circumvented when setting
short_tags = On
within the php.ini used by the apache moduel (usually /etc/php5/apache2/php.ini).
PHP-Module works only, if this directive is enabled, no matter if your code (or the code of the apps you're using) actually uses short tags.
Very annoying to find out, especially since short_tags have been deprecated for a while! None of todays php projects relies on short_tags!