I find the loud trance music that plays in the shop makes me feel rushed and aggressive; it's not a good type of music to have in the background when I talk to people, if it's quiet in the shop and I turn AIM on. If I'm busy I react bluntly and close IM windows. If I'm not busy it causes me to rush things, sometimes wording replies badly.
So far today it has been proven that some people seem to have awful timing.