Either your permissions are incorrect for portal.php or your host has restricted fopen.
I had the same error as Skiilz, I changed the remote file permission from portal.php to 777.
IS THIS SAVE
After did it works.
Great plugin, too bad your site gives my virus scanner a rage kick.
Complaining it's a reported attack site and that it contains a trojan horse at
http://mybb.ithium.net/ name HTML:IFrame-LL [Tri] Malware: Trojan Horse VPS: 100505-1, 05-05-2010.
Perhaps to fix that ?
Wow, Don't go there! I don't use it anymore.
@ Aaron: what about my question