small problem with yum after reinstalling fedora core 6

[Nick Gawronski]

Hi, when I reinstalled fedora core 6 to get some other packages installed
like gnome I did a fresh install and now when I do yum upgrade I get the
following error, what do I need to do to fix this error?
Error: Missing Dependency: system-bookmarks is needed by package firefox
Error: Missing Dependency: gecko-libs = 1.8.0.10 is needed by package
devhelp
Error: Missing Dependency: gecko-libs = 1.8.0.10 is needed by package yelp