The original "welded" couplers are perfectly fine. The issue is with the newer "square" style. On some couplers the roll pin is backing out and the coupler starts to loosen up. I have seen at least four cases of this, though in each case the coupler did not completely fail, and did not result in separation of trailer and tow vehicle. Though, if not noticed in time, it could very well happen.
Kilby has been working on this for some time. They are reassuring all of us who sell, and install, their couplers that we will be receiving the parts to retrofit the affected couplers by week's end or early next week. Like Mario said, Kilby has also stated that they will most likely be shipping revised couplers as early as next week.
All we can do is wait, as Kilby is doing everything they can to ensure they have a safe and reliable product. I hope they get it figured out soon, though, as we have 7 trailers waiting for couplers...
Gabe
www.socalteardrops.com