thanks for your replies.
i am powering it with an AA battery, tried a different battery just in case, but like i say, it worked fine plugged into 3.5 jack on camcorder.
and if it were a cable that did not allow a mono input, again, surely it wouldnt be working on my camcorder ?
i just did another test, right this minute with the camcorder through a 3.5 jack, and it works fine, can pick my voice up no problem from across the room.
its annoying because i bought the ntg2 for 3.5mm usage, in case of emergency, purely because it can be powered from a battery like this.