Fake stock market crash on Dashboard

Apples Macintosh application dashboard has a little thing for following the stockmarket. I seldom look at it, but this weekend I opened the dashboard for another reason and almost fell off the chair when I saw the stockmarket graph.

From the dashboard stockmarket graph. Note the crash in the graph, but the INDU value does not match.
From the dashboard stockmarket graph. Note the crash in the graph, but the INDU (same as ^DJI) value does not match.

It appeared to be a downturn to the lowest value in a year, enough to justify fears that fears of a depression could come back. However, a closer look reveals that the value of the index does not match the graph. Also, when looking at the data in 1 day or 1 week view, the downturn does not appear. Only in 1 month or longer plots.

Puh.