You had mentioned once before, that you sit fairly upright. The more upright you sit, the wider seat you will need. No physiologist here, but I've read that the more bent over you are on the bike, the narrower the area of contact between the sit bones and the saddle. If it is possible to lower the bars just a bit, allowing you to sit less upright, perhaps it might help. If you must sit very upright, might need a wider saddle to support the sit bones. Also, if seat height is too high, you may "rock" on the saddle, which would cause problems. I usually start with seat adjusted so leg is just about straight with the heel on the pedal while at the lowest position, and go from there until I find what works for me. Sounds like you have a good LBS working with you on this, let us know how it goes. Sometimes it just takes a while to get a saddle adjusted to the best position.