I think you need to update your drivers or your word. I am now viewing a 7MB, 856 paged word, which there is no problem at all. I am using X220 with Windows 7 x64 and Office 2010 SP1 x86.
--------------------------------------------------------- [2011]X220-4286-CTO(Brand new, hope nothing bad will happen to it...)[2008]X61-7673-CV2(Slipped upon it, but also working)[2002]X31-2672-BCH(Broke screen, but still working!)
Both ThinkVantage System Update and Microsoft Update are telling me that my system is up to date. It has been a while since this occured, I will take a screenshot or photograph the next time it does.