There is a word document(*.doc) edited with MS word 2003. Other
readers who also have MS word 2003 installed, can open this document
without any problems.
But, Word crashes if the document is opened with any version older
than 2003. What could be the reason for it?

I tried to save the document with 'Save as type' as:Word 97-2003 &
6.0/95 - RTF(*.doc). This time, MS word did not crash. But, the
document also did not open at all.

Does anybody have a clue on the solution for this problem?