The answer
If you upgrade to Office 2010, you will lose the XML functionality, which allows you to export to word. Microsoft was in a lawsuit, which deemed the XML tags Office Accounting was using, to be proprietary. So before Office 2010 was actually shipped, the XML capabilities were stripped out.
If you do upgrade to Office 2010, do not open your custom templates and then save them. The XML will be stripped and no data will come across. You will want to uninstall Office 2010 as well as deleting the OFFICE14 folder in the registry. (Office Accounting looks for this reg key and attmepts to export to the newest version of Word). By deleting that key, Office Accoutning will again export to Office 2003/2007... whatever the newer installed version is.
Here is the exact location of the registry key that needs to be deleted (after uninstalling Office 2010):
1) Click "Start" and then click "Run".
2) Type in regedit and then click "OK".
3) Navigate here:
Computer
HKEY_LOCAL_MACHINE
SOFTWARE
Microsoft
Office
4) Delete the "14.0" folder.
NOTE Microsoft skipped the number 13... just an interesting fact.
5) At this point, I would restart to refresh the registry, then run a repair on your previous version of Office. (from add-remove programs or by inserting the 2007/2003 CD)
6) Export from Office Accounting as normal.