[xwiki-users] Right access with sub group and ldap authentication

Hello, I try to resolve an right access issu with our xwiki 7.0.1. I use LDAP authentication to access at our xwiki. Everyone have read access and a main group have write access on a space (unfortunaly big boss is "afraid?" about wiki spirit: 'everyone can edit'). Main editor group contains some subgroup (like manager, comm, etc.) with users in it. I encountered a strange behaviours: on my developpment platform, rights access work well but on production platform (behind a reverse proxy), right acces working randomly: sometimes main group editors lose write access. I tested with a test ldap user with exactly same rights/groups on same space with same rights access, on my developpment platform and on production platform. Main editor group can write only on my developpment platform :-( Do you have an idea of my problem or a way to identify the source of this problem? I can try to restart production platform in last resort... Maybe the poblem come from some wrong cache on web server? Note: If I don't use sub group and fill main editors groups with users account I haven't problems. Thxs for any help Pascal B