I am having this problem right now too on my Peugeot. I filed down two sets of 9.5mm cotter pins and both times they ended up being too loose when I pressed them in. I think the problem was that I ruined the angle of the cotters just like jimmuller did. I ordered some Grade A 9.0mm Peugeot cotters from Mark Stonich this weekend. I hope they work without modification. Cotter pins are frustrating, but I actually kind of like them.