Microsoft Office 2007 has to be one of the worst application designs I have ever seen. I just lost an important document I was writing, because the interface is too broken.
I mentioned before that the MS Office logo in the upper-left corner is actually a menu. In previous versions of Office (and any other Windows application - or Linux/GNOME application, for that matter) the program icon in the upper-left has basic window operations: minimize, maximize, etc.
But Microsoft, for reasons known only to them, decided that MS Office would be different. The program icon is actually a menu, where you can open, save, print documents. And did you know that if you double-click on that program icon, MS Office will close automatically?
I didn't know that ... but I just learned it the hard way. Accidentally clicked on the program icon, clicked it again to make the stupid menu go away. And there went 20 minutes' work on an important document. Now I get to write the whole document again. Gee - thanks, Microsoft.