[CentOS] CentOS 5.6 will not install due to Firefox error

Wed Apr 6 14:02:39 UTC 2011
Gilbert Sebenste <sebenste at weather.admin.niu.edu>

Hello all,

Well, my local mirror now has CentOS 5.6! Yay! But, I cannot
get it to install. A "yum update" and a "yum --skip-broken"
yields me this:

--> Processing Conflict: firefox conflicts xulrunner >=
--> Finished Dependency Resolution
firefox-3.6.13-2.el5.centos.i386 from installed has depsolving problems
   --> firefox conflicts with xulrunner
Skip-broken could not solve problems
Error: firefox conflicts with xulrunner
  You could try running: package-cleanup --problems
                         package-cleanup --dupes
                         rpm -Va --nofiles --nodigest
The program package-cleanup is found in the yum-utils package.

Any ideas? All the packages seem to be there.

Gilbert Sebenste                                                     ********
(My opinions only!)                                                  ******