Facebook friend etiquette?

[freakykittygoddess]

What do you think? Let's say you wished a friend on Facebook a happy birthday, and several other people did, too. If the friend commented on everyone else's birthday post with "Thank you!!!" and "Thanks!", but they respond to your "Happy birthday! Hope you have a great day!" post with "Thank you....." what would you think? Would you think the person doesn't like you?
Well, I looked at some of the other posts after mine like someone said to, and she put exclamations on them. Oh well....who cares. Its not like she and I talk a lot anyways. I will probably just go ahead and delete her. She posts too much stuff about advertising for Mary Kay, anyways.