OK panic over. It seems it was in April '11, this sw rev. The 512 I just got around to unpacking ,was probably before that. Once I plugged it in it appeared to get new sw and the behavior changed.If you use just one input , the 1/2 option disappears and it powers up on the active input and doesn't bother you any more. Makes it better if you have to replace a 510 and don't want to run wires or frig around upstairs