You are running out of RAM and OpenOffice is really heavy... way too heavy. I would also believe that you are using a heavy desktop manager as Gnome or KDE right?. And Fedora is also heavy
. Basically, you will need to optimize your PC:
1) You processor is a bit old for bloated distributions as Fedora. Either get more RAM or increase your swap partition (you'd really need 512MB swap at least, and one more mem-stick of 256 would be great).
2) Drop Gnome or KDE. Go with something more lightweight as Fluxbox or XFCE.
3) Just use OpenOffice if you really have too. Many peoples just need a simple Word Processor with spell check capabilities. In this case, AbiWord wins hand's down.
4) Other distributions seems to be faster with older machines, as Slackware and Debian. Think about it too
.
Good luck!