I'm not really sure. I have a memory from a few months ago when I went through my texting history storing people's numbers as contacts that it said something about the latest contacts not being synched, and I had little idea what it meant by that. After that there was the occasional message about synching contacts, then it stopped. I've been through settings and tried to open everything to Yes, but it still doesn't work.
OK, I have just discovered that the contacts are stored on the phone, not the SIM. That's something, anyway.