Split from this thread.
Folks, I solved my problem by changing settings. I unchecked preferences -> save -> prompt for document properties. Curiously, by uninstalling and then reinstalling office (i.e., by completely following the MS fresh (re)install) those preferences are not deleted.
Thank you for the responses
Okay, this didn't work for me. I think it might have been because I was trying to save to my Dropbox folder. When I saved to my desktop, it worked.
But it would have been better if I could save to my Dropbox folder directly.