You must be talking about the lightweights. In my experience and that of a couple friends, even properly torqued they seem prone to failure as you've experienced. Talley will replace them for you. They seem to be the leupold of rings, working fine until suddenly they don't, with free replacement once you get home. All of which isn't really any help at all if you're out on a hunt at the time. Their QD rings are outstanding however.
I just put a set of the screw-detachable Talleys on a Mauser. Very nice stuff, and priced to match.
No trouble with the lightweights yet. I torque them to no more than 20 inch pounds, and that's held on rifles up to .30/06 with scopes up to about a pound, not for many rounds though.
