Audio Science

I have aftermarket swaybars. On the passenger side rear there is a bracket that holds the swaybar bushing. Atleast I think thats what you would call it. Anyhow the bracket slides in on one side and has a bolt on the other. Well the part that slides keeps coming out somehow. Is there maybe something else wrong other than the bracket. because the bracket looks fine. Has anyone ever experienced the same problem?
Thanks