WHMCS Gold Integration Problem

Hi, i just purchased (OUCH) WHMCSGold Coupons and installed it. When i fill in the configuration info it doesnt save and doesnt show in coupons.php.

Ive tried changing permissions on the files involved but still doesnt save the config.

Is it right that i should trash this as its been a headache from the time i purchased it. Thanks. Much appreciated for any responses. Cheers.