og_menu permission not respected

The idea of og_menu is that group members or group administrators can organise their group content into their own menu. At the moment I see this core functionality broken because the role that has this permission won't see the Menu Settings when they submit or edit content.

Can somebody advice me how to pin-point this problem, that could either be a bug of og_menu or any side effect of the many other modules that I have activated. It would go too far to list them all here, what would be helpful is a way to analyse this problem.