Do you want to save changes?
You come back to your computer after a long break and see a Word document still open. You’re done with it so you close it and are asked, “Do you want to save changes?” Your first thought is, “What changes?” You swear you just had the document open to check something and made no changes to it.
I hate this. It happens again and again. I want an easy way to see the changes its talking about. I want to know if I really made a change, if I accidentally typed a spurious character, or if Word is just doing one of its weird things with templates.
Somewhat related: Microsoft has a number of its employees blogging away. One of the guys, Rick Schaut, working on Word for the Mac often posts about the inner workings and bugs of Word.