Adobe Acrobat X - initial (default) window size to large

I recently changed my monitor and now whenever I open a PDF the default window size takes up 80% of my screen.  I'm using Filemaker 12 to create these PDFs, and the inital view is set to Page Only, Single Page and 100% Magnification.  The problem is the Acrobat window is about twice the size of the page width, covering up the rest of my windows.  I cannot find the setting to specify the default window size?

I'm running Acrobat X 10.1.6, running on OS X 10.8.3

Please advise.