This thread caused me to pull my own Readyload holders out and check them. Sure enough I found that both of mine are also warped. The edge one inserts into the camera first, on the side facing the lens, isn't flat. It's not bad enough to cause a light leak (at least it didn't fail the flashlight in the bellows test). But it seems to be sufficient to effect focus, and it's not stable (it can rock back and forth some) so it could cause focus problems to be worse on either the top or bottom of that end of the holder. Has anyone else seen this? And, are there any other threads out there at the various forums that talk about this problem?