We are having a problem when we enable Ray Pro in Admin > Global Setting > Variables

When we enable it, and then go to /member.php we get the following error:

Warning: main(constants.inc.php) [function.main]: failed to open stream: No such file or directory in /home/nmii/public_html/ray/index.php on line 24

Fatal error: main() [function.require]: Failed opening required 'constants.inc.php' (include_path='.:/usr/lib/php:/usr/local/lib/php') in /home/nmii/public_html/ray/index.php on line 24

It appears to be working even without it enabled in the backend.

Any suggestions ?