I've replaced the ring several times on my Dewalt but even when new it doesn't hold the socket as firm as I would like. So far I've noticed that sockets with a hole in them for the pin will not come off without a fight. I use a small nail through the hole to push the pin in. But if I use any of the three other sides of the socket (without the hole) then they aren't that bad to remove. I kind of like the option.
Are you sure the sockets are not getting wore out?