Bibliography losing all the cross-references in MS Word

Hi,

On behalf of my daughter who is going crazy having to keep re-working some school work under a deadline.

She created an assignment and diligently inserted all her references as citations, correctly credited all the authors by inserting the appropriate citations at the appropriate points and creating the complete bibliography entries. Once she was part way through she then inserted the (automated) bibliography and that all worked fine.

Then she called me in a panic: "My bibliography won't update". I don't know loads about Word at a deep level but I am experienced enough to go looking to make sure that the cross-references were working -- and they were all gone! Where previously she might have had a citation something like "Jones et al, 2003" which you could mouseover and click on to take you to the bibliography, now it was just static text. We had no idea WHY it happened but I showed her what had happened, we rebuilt her bibliography and reinserted all her citations.

She just called me again. It has happened again. She's a clever girl so she's either doing something not obvious and accidentally editing the content, or there's some other reason why this is happening.

The only thing I have come up with is.... could she possibly have started out working on an old Word file that was saved in the old .doc format and could this be the problem? i.e. could it be that she adds all the citations and bibliography (which, I believe, are implemented in the current version of Word by way of 'content controls') but then when she saves the file, without her realising it, she is saving a .doc file (rather than a .docx file) and in the process it is removing all the content controls which I don't think that older file format supports.

Could it be that?

Can anyone think of anything else it could be?

Thank you

Alastair