This problem has developed recently. (I am recording into a laptop using an interface box and Mixcraft software.) When I record a second track and play.them both back, it is as if they are playing back at slightly different speeds, so that they get progressively out of sync as the playback continues. (This is visible.on the waveforms too.) This is not "latency" as I understand the term, which would produce a constant delay, not one track being "stretched" relative to the other. Anyone have insight? Help!