I use Ubuntu 12.04 and LibreOffice 3.5.7.2.
Would upgrading to 3.6.7 or 4.0.4.2 be a solution?
The doc and docx filters have been updated in more recent versions of Libreoffice.
To install it on Ubuntu 12.04, it’s best to add a PPA. For the latest version at time of writing (4.1), open a terminal and type:
sudo add-apt-repository ppa:libreoffice/libreoffice-4-1
followed by
sudo apt-get update
and finally
sudo apt-get upgrade
If this does not upgrade libreoffice then type
sudo apt-get install libreoffice
You now have a shiny Libreoffice 4.1 installed. Test your doc and docx exports and hope the problems are solved.