The script is WordVertister ([url removed, login to view]).
The problem is with the /buy/*word* that won't go to the paypal buying page.
Script installed at [url removed, login to view]
Script demo: [url removed, login to view]
Maybe you have one and it works? Do you
know a solution (fix) to this problem?
I attached the WordVertiser script ZIP file for you to try it on your own host.