I don't know if this will work for you or not, but I took mine apart for a good cleaning, and tried to bend the locking section of the liner inward a bit more. When I got it all back together, it seemed to be more secure. If all else fails, give EKI a call and see what they can do. I've never had to have a repair done by them yet, but the people I've heard from who have say they are top notch. I seem to remember one guy on the forums mentioning that he asked them what size the screws for the scales were, and they sent him a bag for free. (Maybe they charged shipping, but hey.......pretty good service if you ask me.)
Hope this helps
Woody