I also install RPMs from OO.org. To make file associations work, you have to modify /usr/share/applications/defaults.list
here is what i did, to make it work: *cp /usr/share/applications/defaults.list /usr/share/applications/defaults.list.orig sed -i 's#openoffice.org-1.9#openoffice.org3#g' /usr/share/applications/defaults.list*
I hope it helps
BR
Janez