Sometimes when rezzing on a mesh object, not only does the item fail to rez, we get a false error message which states "The object failed to rez because the owner of the land does not permit..." etc etc. This gives the false impression it is a land setting issue, when in reality it is a rez-on-mesh problem. When the item is rezzed on bare ground or a standard prim, it rezzes first time every time, with no error message.