When I start Excel (2007) by double-clicking an .xls file, the program opens
but without a spreadsheet in it. There is a "Get Started" tab at the end,
and the opened file only shows up when I click on that tab.

I really have no need for the "Get Started" tab, and I'd really like to go
straight to the spreadsheet I opened.

Oh, and yes, the "Ignore other applications" box is unchecked.