[Gus[_3_]]

I have Vista Home Premium installed.
When I insert an index in a Word (2007) document using a concordance table
(also in a Word 2007 document) the index appears OK, but if I then save the
document and try to open it, it tells me that It cannot be opened because of
an error. Luckily I had a back-up copy!
I have had that problem once before with another document when inserting an
index this way but never with Word 2003 (and XP). Has anyone come across
this before?
Curious
Gus