How many blacks are in Austria? Not too many.
Anyway, whites are badgered by messages from media about how we don't ALLOW blacks into our communities and how we EXCLUDE them from our lives, but it seems like it is often the choice of blacks to separate themselves the majority of the time. You said you hang out with blacks MOST of the time. Which is fine, but it does affect perceptions. Because most blacks do this. We can all share anecdotes of this, wherever we live.
It reminds me of how I couldn't get a friend who was black to move into a non-black neighborhood. She wanted to be with people like her. Well, what are people going to think if they see that over and over?