Sprayed my wheat today and it happened in two different fields.  I sprayed the headland, then toggled the master switch to off and then when I went to  switch it back on, the sections did not change from red to yellow, then after flipping it back and forth a little it would turn on and off correctly, but my ez steer would not engage even though the steering icon was yellow.  It would turn green and then instantly back to yellow with out the ezsteer motor even twitching.  I have the 750 wired right to the battery (I forgot the double check the connections though).  I have 4.01 in the 750 and seem to remember someone having the same issue, but could not find it in a forum search.  If I restart the monitor everything returns to nomal.