I just today downloaded the 727-200 expansion and during my first flight I did as described, clicking on the large EP and then checked the FE panel to find the external power light on.  I changed the switch to external power, started the engines and took off.  Soon after takeoff I couldn't get the autopilot to turn on and checked the FE panel.  The external power light was still on.  After engines start on the ground I had clicked EP to turn it off, but in flight it was still on. I clicked on the FE panel switch to turn off EP, but no change.  I clicked on EP icon, no change, the panel light still showed EP connected.
What's up?