Guys, keep in mind that GM has always had a "feature" that did this to keep the occupants from jerking forward and back in the case of an accident. The first jolt from the accedent (and also extending the seatbelt almost fully out) will engage the safety lock. once engaged it is designed to rewind as much belt as it can and hold it until the belt is released andallowed to fully retrack. I think the real issue here is that the seat belt is either short so the feature is engaging too soon or the locking latch is too sensitive. In either case they will replace the seatbelt if it's being too problematic. there is just no real gaurantee that replacing it is going ot fix the problem.