BP-Fun layout problem with private messages

My site uses the BuddyPress Fun theme (using BP-Fun Child, of course). When a member views their Inbox, the message list and content is not visible. By using a Firebug to inspect the stylesheet we found the content to be behind the right sidebar inside a 1"x1" box, not within the main content area. I have tried switching between a different css layout and the default.css, with the same behavior. We have tested Firefox and Safari, same behavior. Switching to the default BP theme fixes the problem.

Anyone have any similar experience? Any ideas?
I've attached a screenshot, sorry I can't direct link, my site only allows authenticated users.