I suspect you are running OS X 107.x (Lion) because this is the standard behavior for this version of the OS.
It seems like whenever I try to open a pdf, numbers, and pages files it opens more than just the file I opened. It seems to open several recent files in that same extension type. For example, I might want to open just one pdf, but all of a sudden 5 other pdf files also open.
I've been searching for a few days all over the web and so far nothing I found helps resolve this. Anyone out there have any tips?

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