Redux: REI Flash 65 pack

The waist belt and shoulder cinch straps start to loosen up after a few minutes--that lets the load down on my buttocks and lets the load fall rearward.  I was thinking this was endemic to the pack & began to look at other packs in the REI Oly store. REI chick came by and we looked at another Flash 65 pack whose straps didn't slip. Bring your pack back for an exchange, said she.