I have read that 'Unknown characters' from cutting and pasting can cause these errors but I am removing these and it still doesnt work. Even opening the document in Word 2010 and then saving it will currupt the file.
We have Version 3.6.1
Licensee: Oracle UPK
IE Version: 7.0.5730.13
Service Packs Installed:
ESP3 for Developer 3.6.1 or 9.6.1 
ESP3 for Developer 3.6.1 or 9.6.1