Eliminate multiple windows when opening workbook

Using 2007 I was editing a workbook and used View, New Window to open the file in a second window, so I could use Arrange All to view two worksheets at once.

Now every time I open that file, it opens in two windows. I have tried closing one window, and doing an explicit save, but that doesn't work. How do I force the file to open in a single window again?

I have tried closing one window

...then saving the workbook

That worked for me in XL2010.