i purchased one of these last week, to use as a headtorch on an all night mtb race, so last night i tried it on a night ride, after 20 minutes on the high setting it went very dim, so i turned it off. On getting back to the car i tried more new batteries and it was very intermittent in turning on, the light level would not adjust and it was going from bright to dim and back again, once at home i tried it with the original batteries which resulted in a very hot top cap (the switch) and batteries, so i put it back in the box ready to send back, has anybody else had this problem? to me it seems like a bad connection across the switch contacts, but i could be very wrong any ideas?