No matter, I got it.
The problem is with the field lenght, varchar(255), while in your case the lenght of the url is 282, so the last part was trunked. But, when I try to add the foreign key searching for the "exact" match, I don't find it, so this raise the error.
I'm working for the best solution to fix this in the next version. Meanwhile, the best way if you have MySQL 5.0.3 of newest, is to increment field size. So, you should alter tables as follow:
ALTER TABLE `jos_redj_referer_urls` CHANGE `referer_url` `referer_url` VARCHAR(330) DEFAULT '' NULL , CHANGE `domain` `domain` VARCHAR(330) DEFAULT '' NOT NULL COMMENT 'The \"host\" part of the referer url';
ALTER TABLE `jos_redj_visited_urls` CHANGE `visited_url` `visited_url` VARCHAR(330) DEFAULT '' NOT NULL;
The next version will include a better solution for this problem.
Thanks again for report and let me know if you need help to fix it.
Regards,
Luigi