Benny you the man, you the man!!!!
Question to any Archos support person then : what does the On-Off button on the left do? My interpretation was that this was the Controls On/Off switch. And you know what, if you are charging the unit with usb and simulatneously hold the play/pause button and then move switch to Off, it locks the controls!!! Unfortuantely if you do same thing WITHOUT the usb plugged in, then the unit just switches off. Personally I think this is a bug...
Small beer people may think, just I use it for long runs several times a week including country paths/hills, and breaks up my rythm having to stop and mess with controls cause I have accidentally knocked them!
So thank you Benny for taking time to let us know.