This could be the error in Word 97 described here: click here
"WORD97-0013: If TOOLS > AUTOCORRECT > AUTOTEXT > SHOW AUTOCOMPLETE TIP FOR AUTOTEXT AND DATES is enabled, then entering a date such as 28 September 1999 will cause AutoText to suggest 1999-09-28. Pressing RETURN will cause this suggestion to be inserted in the document. When typing a letter, it is very likely that a user will indeed press RETURN after entering the date. There doesn't appear to be any method of enabling the normal AutoText entries but not this date feature. Nor does there appear to be any method of specifying the date format. This feature does not appear to honour the date format specified in Control Panel's Regional Settings, nor the choice of default date format in Word's INSERT > DATE AND TIME option"