I think I am one of the many who have had this issue with my Super Avanti. I bought it about a year ago and on the first few trips I noticed all the buckles were coming loose. At first I thought I was going dippy with old age and retightened them, but soon realised they were working loose during a single trip even between pitches. I contacted Petzl who sent me the anti slip keepers - no offer of a return and replace of the whole item. It seems to me to be the result of the webbing being stiffer perhaps or the buckles, or a combination of the two. The latter look like they are laser cut whereas older buckles seemed to be thinker in my memory? Anyway, the keepers are rubber O rings for the leg loops and an elastic band I think, for the main buckle. Just lifted them out of the box to photograph them and you can see the rubber bands (O rings) clearly in place. The elastic keeper is not in place over the main buckle in the photo, but you can see how the stiffness (or slickness) of the webbing material is already lifting the original keeper-flap back out of the buckle just through handling the harness after washing it down. Not a brilliant solution from such a major equipment supplier for a design issue, but they do seem to work when in place.