You might want to try a firmly-padded saddle instead of a soft one. With a firm saddle, your sit bones' region supports most of your weight. With a soft one, they sink in, allowing the soft tissues around them to take pressure too. Make any sense...?

I hav a WTB saddle on my mountain bike, one of their upper-end droop-nosed SST models with a high-quality leather cover. It has an ideal amount of firm padding, and a shell with moderate flex (plus it's not ultra-skinny). If you get a WTB, be aware that they have top-end ones with the nice leather covers, and then they've got the baseline models...