Is there any way to avoid anomalies like this one in routing? I don't seem to be able to route the shortest distance. Not with basecamp an neither with my Garmin Oregon. I suspect my maps being bad or having disrupted roads or something.

Do you get the same error when routing method is set to pedestrian (wrong vehicle type), or the travel direction is reversed (one way street)?
DRTBYK, how did you know what map the OP was referring to?