Okay, now this is completely, utterly weird... After posting that I quit Poser and was doing some Photoshop stuff for a while. Then i went back into Poser to show my wife the weirdness and it didn't do it. It seemed fine. I could twist it and shape it and it maintained the curve. Only the thumbnail was there to prove I wasn't crazy. So now I have the most useless prop I've ever created -- a fully posable pretzel.