My guess is that your saddle is too soft and isn't properly supporting your sit bones.

There are lots of good saddles out there, but it's all about individual preference. What works for one person, won't necessarily work for another. But as a starting place, you might take a look at Terry Precision Cycle's website. Terry divides their saddles up by "performance," "all around," "touring" and "recreation." However, IMO you shouldn't get too hung up on what kind of bike/riding a saddle was intended for. What's most important is that is fits your body, provides support where you need it (sit bones) and doesn't chafe or put pressure on parts that don't need it (your girly bits). It often takes some experimentation, but Terry has a great return policy. I, personally, have the Terry Butterfly Tri Gel.

http://www.terrybicycles.com/saddles/product.html?t=w