I have been checking the difference between the php.ini files and one of the differences is short_open_tag which is 'on' on my local machine and 'off' on the server. I turned it 'off' on my local machine and mod_avpano reports an error:
ERROR: File does not exist
localhost/joomlatest/<?$interfacefile ?>
I think it is quite common for this setting to be 'off' on modern production servers so it might be worth updating the source code to allow for this.
There are a few other settings that are different so I will see if there are any others that are causing problems.
regards
Trevor