You should see 2 buttons:
# Identify city and state by zip code (entered above)
# I will enter the location:
Have you tried them both to see what comes up with each one? I use the first one, I put in my zip ONLY and don't fill in anything else and by the time my listings post it DOES have both city and state. (However I can't see city OR state on the Auctiva page). I hope this is what you meant