I'm right there with you both on this issue. I have been living in Charlotte for about 2.5 years now and have had almost no luck on dating sites looking for athiests. I did find one on okcupid.com that worked well for a while, but we broke up for completely different reasons (i.e. normal relationship reasons). I have also dated a supposedly open-minded baptist for about 6 months and while everything seemed to be going well... it was a tough break-up. She had a daughter that went to a Christian school and I was cool with that. She went to church on her own every week and I was cool with that too. She seemed to be ok with me not going for a while, but then I think it just ate at her too much. She would never say it, but I could tell.
She ended up leaving me for my best friend, because he was open to going back to church. Pretty crappy thing to do, but whatever. They're happy now and good for them.
As for me, I have been pretty much alone with my cat for a good while now. I've also decided that finding an "open-minded" believer is just not going to work and so I've decided to just stick to searching for an athiest, agnostic, etc. I guess I'd even consider looking outside of North Carolina, but am a little to apprehensive to long-distance relationships.