This info should be part of the official documentation (or even better, as a note on the admin screens when listing or adding a new View). Almost every time I use MB Views, I spend a few minutes trying to figure out why the views are returning 404... every time I go through this process of thinking... "It's broken... but it can't be... MetaBox is perfect... It's my site... I need to wipe everything and do a clean WP install..." until I eventually start googling and find it in my search history and then end up on a forum post. And every time re-saving the permalink structure fixes it. 🙂 maybe one day I'll remember that right away!