Error opening docs after index inserted WORD 2007

[OFF121]

Hi folks,

My students keyed in a rather long document, formatted the document, added a
cover page, and references with no problem. The file will save and reopen as
expected. When an index is created using a simple concordance file and the
file is saved it will no longer open. We get an unspecified error message
that tells us the file will not open.

I've found a work around but it is not satifactory. The only way to get this
file to work is to create the index after the plain text is keyed and before
any formatting or other components are created. If the index is created
first, then the formatting, TOC and remaining components are created the file
can be saved and reopened.

Any ideas what's going on? Could this have something to do with the code
behind the cover page? Could this be related to Word automatically trying to
open a Word 2003 compatible file when browsing for the concordance file?

This problem occured for my entire advanced Word class, documents created in
our computer lab and on student home computers.

Thanks!