Word XP document produces 100% CPU load

I have a problem with Word XP.
When I open the document everything is fine, when I click the footer (for edit), everything is fine but when I click the last line in the Footer the CPU gets to 100% and Word freezes.
This happens with 2 documents, with other documents the user can edit the footer without no problem. As far as I can see the last line contains only bold text (as Word freezes :D).

Did a detect & repair, didn't help

Someone has an idea ?

is your word program updated with all the security updates?

Why use word? USe openoffice. Free and compatible. http://why.openoffice.org/

OpenOffice is out of the question due to company policy :( .
And yes, Word is up to date :)