Why are my automatic settings creating blurry images?

That depends on what kind of blur is that.

1) If its motion blur, you are shooting in low light with low shutter speed and without a tripod. Your hands are not steady.

2) If its a lens blur:

2a: You are again shooting in low light and its difficult for auto-focus to distinguish between contrasts.

2b: There is something else going on with your lens focusing motor. (I ripped my auto-focus system out of my lens long ago, made my lens lightweight and more reliable).

Note: Though I wouldn't recommend 2b's example. That would cost you your warranty.