What I think happened was I had the saddle tilted up too much and was therefore riding it on the rear edge. Wanting to try to actually utilize the flat surface of the saddle I spent an 8 mile ride doing so resulting in spikes of pain in the groin for the next few days (but not immediately after).
For today's ride the saddle was tilted more horizontal but still up a bit in front, exactly how you have recommended jcm, and I sat halfway on the flat face and halfway on the rear frame. This actually felt pretty good making me wonder if this is the right way to sit on this saddle. What part of the saddle do you place your weight on for the B72 style cut models?