heyas; should be bent. i read somewhere that poser uses a slight initial bend in body parts to know which way to fold them up when you use ik. if the legs were perfectly straight, it's a 50-50 guess as to whether the knee folds forwards or backwards ;) you might also fix this by hand, timoteo. just advance forward frame by frame until you get to the jiggling frame. try deleting the keyframe for that, and perhaps the ones around it. (as i recall, using the walk designer makes every frame a keyframe.) you can adjust those frames by hand, if you have to.