Empty RosterGroups are automatically Deleted on rosterModified() Event

If I create several RosterGroup instances in my GUI, once the first user is added to one of them, a rosterModified() event is sent and it deletes all the empty RosterGroups from the server. This is absolutely killing me, I’'m trying to work around it by caching empty Groups and adding them again after the rosterModified() event arrives, but this is not a good way to manage this.