what speed should photos be burned to disk at
Actually, that is very true. OS disks should ALWAYS be burned at the slowest speed to ensure the critical data is not corrupted from disk wobble (causes from high speed revolutions). I burn CD-ISO's at 4x and DVD-ISO's at 1x. And about 1x not being supported by any current drive..well..ot exactly true for DVDs, media rated for higher speeds don't like being burned at too low speeds, also you can't burn at 1x as that is not supported by any current drive, the lowest speed for DVD is 4x. You shouldn't be so concerned about speed, more important is the brand of the media you are burning on.