If I'm at a party it's usually because its at the house of a group of friends, and half of them will be hiding in their rooms anyways. We all tend to dissapear into the rooms for a bit durring any party anyways, and come out to steal food.
I find that if a group of people are too different, its pretty natural to not want to talk to them.
If everyone at the party is different than you, then shutting down isn't at all surprising. You really shouldn't have to force the interaction though, it isn't all about trying to get along for another's sake, you gotta remember to think about your own fun and enjoyment. If they dont hit upon something you feel like talking about, can't blame yourself for not wanting to get involved.
Maybe next time, pick a spot in the kitchen and start mixing drinks (Non-alcoholic is more of what I mean, see below). You'll be the party favorite without having to strike a conversation at random to a room of strangers. I am a cooking type though so this is more my thing. Hell, if you've got mad skills and an open kitchen, flambe baby! Everything is better with fire, especially a party. Its not as hard as it looks either.
Drinks are easy, if you have warning and a friend is hosting (or even you if you get brave and ambitious) just have these things on hand: Crushed ice or smaller cubes. Buy bagged. Pineapple juice and other fruit juices, coconut syrup and grenadine, (you can usually find it in the pop and water Aisles at the store) lots of either Sprite or just carbonated water, and straws. You can make something really good with just a glass full of ice, a teaspoon each of grenadine and coconut syrup, fill the glass halfway with pineapple juice, and the rest with sprite. Less syrups and use carbonated water to make it less sweet. Its pretty fun to make/watch too.
Okay, a harder one, but if you're brave, go for it! Here's some links for making one:
http://whatscookingamerica.net/flambe.htm
http://whatscookingamerica.net/Fruit/BananaFoster.htm
Basicallyyou take sugar and spices, dissolve them in a frying pan over a gas stove, (sorry electric) add some fruit, add some really high proof alcohol, make it hot and tip the pan over a little into the flame. The whole thing lights on fire and you stir it till it stops. Put the contents of the pan onto a plate and add ice cream. You have made this party better, with FIRE.
The moral of this [crazy] story is that if you don't have anything to talk about, make something. Food is the easiest, and people always eat at parties. You'll be too busy talking about food (or FIRE) to worry about not having anything in common.
...Okay one last recipe. Easy layered dip: Sour cream, cream cheese, salsa, shredded cheese, bowl. Bottom layer, salsa. Next layer, cream cheese (get the whipped stuff and warm it up if it wont co-operate). Next layer, more salsa. Second to last layer, sour cream. Last layer, just sprinkle cheese on top. You can make this a thick layer though. Make it in front of everyone if you can! It'll go fast so you can make another.
I love food
I think it might be the conflict between my introverted intuition and extroverted feeling: My feeling tells me that I should go for the person who I care but my intuition tells me I don't feel like it... 
