Not all Lippert frames are created equal. Some RV manufacturers will use stock or off-the-shelf Lippert frames - these are the ones that seem to give problems. Other higher-end manufacturers will design their frames and farm the construction out to Lippert under strict QC guidelines - DRV is one such manufacturer. I've owned DRV 5th wheels since 2004 and have never had a frame problem; in my 11 years of DRV ownership and frequenting the DRV owners' forum, I could probably count the number of frame problems I've seen reported on one hand.
DRV Mobile & Elite Suites frame
Rusty
DRV Mobile & Elite Suites frame
Rusty