I have a Besler Dichro 45 and a Gralab 545 timer. The timer works perfectly with my old D2 enlarger. With the Dichro 45 head the light is on all the time when plugged into the timer. The timer can be off or on, no difference. I suspect the 545 timer switches neutral instead of hot. Has anyone else had this problem with the Dichro45 and the Gralab 545?