Well I don't know how this could change but you might check:
/periodic/cupid.php

Line 21 find: Should say something like:
require_once( '/home/jaijine/public_html/inc/header.inc.php' );

Possibly you don't have the correct path to the file in cupid.php in
this case "[path_to]inc/header.inc.php

You need to make the path_to part the actual path. Which the script
sets itself to during installation.

Sounds like you do not actually have the path set at all. Like I said
I don't know see more how this would happen unless you restored the file from
the original .zip file which didn't have this info written to it yet.

If so be sure to check the others too:
/periodic/cmd.php
/periodic/cupid.php
/periodic/notifies.php

Also:
/inc/header.inc.php

And:
ray/modules/global/inc/header.inc.php

To verify that all paths are correctly set.