You'll find that they will talk to you again, which basically means you've said and done nothing wrong.

I guessing that you feel intimated by your co-workers so its only natural that your avoidance is going to be on high alert. We are sensitive people and dependent on who we're talking to with our response being some kind of internal metered anxiety... for example you may have one person you find easier to talk to than another.

I'm sure you were friendly and thats what they will take away from your conversation and thats what will bring them back to you.

btw, cool user name!