The problem here is that users with Office 2003 will create Word 2003 (XML) files. Word 2003 files are NOT compatible with previous versions of Word. In other words, old Word versions cannot directly open them.
The solution here is a simple one: as soon as the file is converted, go to “Save As…” and in file format choose “Word Document” instead of default “XML Document”. Word will the save the file as an ordinary Word file that can be viewed by users with older versions of Word.
This article refers to Able2Doc, Able2Doc Professional, Able2Extract and Able2Extract Professional.