We have received reports on problems with the persistence of the catch content with OutWit Hub add-on on Firefox 19. We are working on the fix at the moment. This doesn’t impact the standalone version. You can therefore use this one in the meantime, instead of the add-on, as it doesn’t depend on the Firefox update calendar.
[update] Version 184.108.40.206 is online for download. (Not yet as a general update.) It corrects the problem. Please tell us if you still notice a problem on this issue.