According to a post by Christopher Carfi on the blog Social Customer Manifesto, Word 2007 saves files in a .docx format, making it incompatible with previous versions of Word. I don’t have Office 2007 yet, so haven’t run into this problem, but as many of you upgrade, and you’re sharing files with colleagues who haven’t, you’ll probably experience this compatibility issue. Thankfully, the post offers a work around:

“Office” button =>
“Word Options” button (it’s hidden down at the bottom) =>
“Save” link =>
“Save Files in this Format” = Word 97-2003

According to one of the post’s comments, the same sequence works in PowerPoint and Excel 2007.

Thanks to Christopher for the heads-up and to his friend Korbett for providing the work-around!