It took me a while to figure this out, but I couldn’t change the default language for documents in OpenOffice. There are various options, but none of them would stick. I did a little searching on the wonderful FedoraForum.org and I found this thread.
Although the thread mentions FC4, the long and the short of it is this, the default system language is set in /etc/sysconfig/i18n and that is probably set to US. I switched to en_GB, rebooted, and bingo, it works. Beautiful!