I can't see anything wrong. It's possible that some of the cylinder has not been selected (such as the top face which isn't in view). Otherwise, I don't know. As for your zoom problem, I've no idea what's going wrong. Again, try a different interactive renderer (click the circled arrow on the right of the modelling room window). Otherwise, all I can suggest is you save your work often, using a new file name about every half hour so that if you get a currupted file you don't loose a lot of work. Mark