When standard isn't standard

I haven't gone through the UI Guidelines for the Mac, but one thing that has been pretty common across most programs is that you can scroll when your cursor is overtop a window, even if that window isn't in the front. This has caused a few issues in my life, but none that have been terrible. 

However, Microsoft Word does not scroll unless the window is in Focus. Which is really starting to irritate me.  My day job involves doing a lot of research and writing, and I have an index file that I need to scroll through fairly regularly. Instead of being able to hover over the open window and scroll, though, I have to click on the window to bring it to focus, scroll, then go back to my main document, click on that (losing where I was in the process), and start typing. 

This is irritating. And I don't know why they did it that way. Excel allows you to hover scroll. 

Sigh. Just a pet peeve.