Dog aggression towards ONLY me...

Question
I met my best friend's of 11 years dog today, at her house where there was a large group of people for a party. At first he jumped up and down on me and seemed genuinely interested in getting to know me. He let me pet him and he was very friendly to everyone else and let them pet him and play with him.

Then all of a sudden when I bent down to pet him some more he began to bark at me. It didn't seem overly aggressive but still it was surprising and unexpected, and not something I wanted to push. From then on, he wanted to do nothing but bark at me, he would approach a little and then bark, sniff at me and then bark. I thought it could be that I have a strange dog on me, but many of the other people at the party had both dogs and cats and were not barked at. They had to put him outside. At one point I sat in a chair, hoping to get more on his level so he wouldn't be scared. He let me pet him for a second sniffed me and then barked some more.

I am an avid animal lover, and I have NEVER met a dog that didn't like me, unless they didn't like ANYONE. I can go up to dogs in the street and they will want to play with me and get petted by me.

What did I do wrong? I don't remember any aggressive or incorrect behavior. I want to be able to go over to her house, what can I do that will help solve this?

Answer
Some dogs are more sensitive to things than others.  Stand tall, a toothy smile, and look somebody in the eye works very with people.  Along with patting the top of their head, dogs view that as aggressive and challenging.  Think if that was what you were doing.