NYC: Rather than going around the horn on this argument, I would probably email her back and say "I haven't heard from you about the trip. If I don't hear from you on X date, I'll assume the trip is off and make other plans." Period. Show her you're serious. You don't have to chase after her. Friendships, like relationships, should be even sided. She's holding a grudge and expecting you to call her to make contact. I agree with Prodigal about the birthday thing. You can't expect her to change, but you can set your boundaries and then remove yourself from the situation if those boundaries are crossed. Arguing with her isn't accomplishing anything and is only making you miserable. If your friendship is important to her, then SHE will change her ways to be friends with you based on your boundaries.
One more thing...as someone who also had a childhood friendship that lasted forever and eventually died, sometimes friends around for a season in your life. It's hard to let go of the ones that have lasted so long, but sometimes it's necessary. I still think of my friend occassionally but I have no desire to contact her anymore. It just became too much like work! I'm not saying some friends aren't worth the compromise (because they are) but it's important for my sanity to start protecting myself. If our friendship can grow from that, then great, but I'm not hanging my head out there to be chopped off anymore.
