There were some changes between the older versions of Office & the old Office 97 version... just as there were changes between Office 97 & the later Office 2003 standards.
The last major formatting change I was aware of was with Office 2007 (i.e. the switch from ".doc" to ".docx"). However, since Microsoft has a free download for Office 2003 that lets it read the .docx format & convert it to Office 2003 format, I haven't really noticed any formatting change issues show up.
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