I have a 70 series with same problem:
Just today we did a little experimentation and this is what we found:
Try raising the height of the drain hose. We have a plastic drain hose (similar to a vaccuum cleaner hose) with a rubber "U" pipe at the end of it, which sits on the edge or our utility sink. Having the same problem you complained about, we emptied the tub, set it to "high" and let it fill up. Sure enough it wouldn't cut off. It filled and then kept running out the drain hose. I grabbed the "U" pipe and raised it up just past my waist height (about 10 inches above the sink level) and it shut off and went into the next cycle!!!
WOOOO HOOOO just saved a couple hundred buck!
Ben
October 2005