Every time I try to migrate users at my company from MS Office to OpenOffice, the story is the same. They accept it at first, but a week or a month later, they come back to me and say "Some of my word files don't work right in my office. can you give me the same version that [name] has?" where [name] is the name of a person who still have MS Office 2002 on their computer.
When I try to track down specific complaints, I usually find a subtle formatting problem that breaks a table over a page boundary, or makes an awkwardly formatted page, or a font that ends up making a particular line of text just one pixel wider than it used to be causing a reflow. Stuff like that.
I get *almost* the same reaction from people when I try to upgrade them to MS Office 2007. (with higher emphasis on "I can't find feature X" and lower emphasis on "this document formats wrong")
There is no likelihood man can ever tap the power of the atom. -- Robert Millikan, Nobel Prize in Physics, 1923