Answers: if you are using Word 2007 consequently it is good surrounded by .docx format which is incompatible beside Word 97 to 2003. thus it cannot be open next to elder version of Word.
cheers
it happen when you use the bureau 2007 software and on the other computer that you trying to uncap have an elder reworked copy. Or viceversa.
organization 2007 save contained by ####.docx instead of ###.doc