Facebook chat etiquette?

Most people on Facebook friend lists are mere acquaintances or you don't them at all. But when your talking with good friends over chat, don't you think it's a bit rude for them to ignore what your saying or respond rudely to your comments? I have a few friends who do this to me and outside of seeing them for real, it seems like they don't really like me at all. How would you respond to this kind of behavior?