Kelty is aware of the flaw. If you call them they will send you a new pack. Unfortunately a new pack doesn't help because they all have the same issue. I tried three different packs that all had a slipping pin. This instructable shows how to fix the slipping pin yourself.
- Foam mattress (yoga mat, gym pad)
- Super glue
- Coin (1 U.S. cent)
Step 1: Why the Pin Slips
Step 2: Fixing
1. Cut a few small round pieces and one larger piece from the yoga mat.
2. Push the small pieces into the hole into the lumbar pad.
3. Push the bigger piece in last so it overlaps the plastic ring from the underside.
4. Put a few drops of superglue on the exposed mat.
5. Press a coin into the glue. A penny is about the right size.
7. Let the glue settle.
Hope this fix works for you. Pin slippages stopped for me. Happy walking!