PowerPoint works like this, too -- there's only one close button. Each time
you click it, a document closes, and when you have only one document left,
closing it closes the whole program. It made me NUTS during beta.
If you go to Office Button | [program] Options | Advanced and uncheck "show
all windows in taskbar," you get two close Xs, and you can close the last
document without closing the program. However, for me, this was a
non-starter because it was a PITA to use the View tab to change windows -- I
really do prefer having the files as separate icons on the taskbar. (View |
Switch Windows | Document seems to take a LOT longer -- not to mention more
thought, which is disruptive to my workflow -- than just clicking the other
document's icon in the taskbar.)
So I added the Close button to the QAT and trained myself to use it. That
enables me to close all documents without closing the application. This is
the best solution I've found.