One fix that used to work on corrupt Word 2003 documents, was this:
(1) we use a document management system to "Check Out" the original file to your Desktop so you may not have this step
(2) close Word
(3) open Word
(4) open the document and make ONE change only - say to the top of the document (you can delete this part later, after the last step is done)
(5) save this same document to your DESKTOP but with a completely different name - like "Recovered file.doc" - it does not matter what you name it as this will change anyway
(6) close this file too and then close Word too
(7) go to your Desktop
(8) go to your "orginal" Word doc. and press F2 on the filename and copy it (Ctrl+C)
(9) delete this "original file" now
(10) stay at the Desktop and go to the filename of your new "Recovered" file and paste the copied filename over the existing filename
(11) go back into Word and using your document management system, click on "Check In"
(12) when it brings up an option to "Replace the existing current version" click on that and OK
(13) your recovered document should now be there with the additional new text you added (which you can now delete if you want)
(14) looking for any other oddities - if any as there should not be any - and your doc. should now be uncorrupted. You should now be able to use this file without any problems.