[Plugin: WP-bit.ly] Problems saving bit.ly account information

Hi!
I’m having some issues on saving the bit.ly account details on the options page. I’ve installed WordPress as a plugin (corePHP) for Joomla, so I think thats what causes the error.

This is the url that show the option page: http://www.mydomain.com/administrator/index.php?option=com_wordpress&task=options-general.php&page=wpbitly

When I click the Submit button the browser requests for this url: http://www.mydomain.com/option.php

And this doesn’t work…

Does anyone know what the right url should be?