I have a Shimano 3N72 dynamo hub wired to an B&M IQ Cyo headlight and a toplight line tail light. Last night as I was riding I noticed that the headlight seemed to alternate between normal riding light and the standlight. The weather was clear and about 70 degrees. The problem did not seem to occur on perfecly smooth pavement. Do I have a fauly connection between the hub and the light? Any opinions/ experience with this problem? Thank you in advance.