The hack was introduced by b0c2e54 back in 2003. The comment about Microsoft Office doesn't go into detail about what breaks exactly. Anyway, I tested Word, PowerPoint, and Excel with Office 97, 2000 and 2003. They all work correctly with this MR applied using an XP prefix and a Chinese IME. For what it's worth, I do prefer keeping the 0xe001 on XP and lower, just to be on the safe side.