Non gorup memebrs are not allowed to Build-up group colleciton even if open

GO to a group that has an open collecciton, but not as a member of the group. (For example using demo/curriki visit http://next.dev.curriki.org/xwiki/bin/view/Group_FoodandSociety/Curriculum ) you will not see the 'build-up' option even thoguh edit is available, and if you view the colleciotn, you do see build-up (http://next.dev.curriki.org/xwiki/bin/view/Coll_Group_FoodandSociety/GotCurricula)