Kanboard + Worpress + Caching =?

I have kanboard successfully installed using MySQL. The root folder in which KB is installed is a WordPress installation, hosted by a third party (not WP). In some browsers, I’m having a problem where the WP cache seems to mess up the pages served by KB. If I pass an extra argument to KB, in the style of:
(base URL)/?controller=BoardViewController&action=show&project_id=1&extra_agr=893745923
… it all works.
Now, please somebody point me in the right direction to solve this problem.