I had a problem with this until I was shown the cure. One has to copy the fonts into a special directory called
fonts:///
I find if I do this as root it goes better. Use File Browser for both getting the fonts and putting them into fonts:///
I have since made a CD holding all my "extra" fonts such that I don't have to go searching a whole pile of commercial CDs every time I do a re-install or some other sort of revision.
Note that there may appear to be glitches in the copying process, but I found that merely logging out and back in solved that problem and they all showed up under OpenOffice and looked OK even on the drop-down font menu. They didn't appear all that well in AbiWord but this app. has disappeared from FC4's automatic install options (yes, there's a special option to download it later but this smacks of Fedora wanting to drop AbiWord altogether).
Hope this helps,
CroombeFP