Using ArcMap 10.1. I suddenly can't show deci-degrees for the Coordinate Display. Instead it shows deg-min-sec. The "Use these units..." box under ArcMap Options is checked and Decimal Degrees is selected. All of the other coordinate displays seem to work as advertised. I set the units to kilometers (as suggested in another answer), restarted ArcGIS but nothing changes. It was working this morning with a previous map.
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