How did you install openoffice 3? If you just downloaded from site and
installed then you may have some issues. I think you would have to run
the programme as root then all the buttons should show up.

Alternatively, add the openoffice PPA to your repos and it should be
taken care of automatically after that, that is what I did. In that
case I would uninstall the OpenOffice 3 package, reinstall the
OpenOffice 2 that is in the repos. Then add

deb http://ppa.launchpad.net/openoffice-pkgs/ubuntu intrepid main

to your third party repos. After reloading you will be told there are
updates for your openoffice package and then that should be most of
your worries taken care of!