Yes, they should be replaced by hyphens (update-desktop-database) and if after you fix /var/lib/dpkg/info/openoffice.org.postinst, you still get an error on the same line, more likely it is because you are missing the desktop-file-utils package that contains the update-desktop-database file.
BTW, the KDE and Gnome integration in 1.1.3-3 is amazing, kudos to the Debian Openoffice team. Erik.
