update doesn't really work

[David Howland <dhowland ecs umass edu>]

I've set up a 7.3 machine to update to the fedora-legacy project using 
yum.  It doesn't really seem to work at all.  Any help would be greatly 
appreciated.  Please CC my email directly, as I am not subscribed to the 
list.  Error follows.  Thank you.
-d

# yum update
Gathering package information from servers
Getting headers from: Red Hat Linux 7.3 base
Getting headers from: Fedora Legacy utilities for Red Hat Linux 7.3
Getting headers from: Red Hat Linux 7.3 updates
Finding updated packages
Downloading needed headers
Resolving dependencies
.....identical dependency loop exceeded
package mozilla-psm needs mozilla-nss = 1.0.2-2.7.3 (not provided)
package mozilla-psm needs mozilla-nss = 1.0.2-2.7.3 (not provided)

$ cat /etc/yum.conf
[main]
cachedir=/var/cache/yum
debuglevel=2
logfile=/var/log/yum.log
pkgpolicy=newest
exactarch=1
exclude=kernel*

[base]
name=Red Hat Linux $releasever base
baseurl=http://download.fedoralegacy.org/redhat/$releasever/os/$basearch
gpgcheck=1

[updates]
name=Red Hat Linux $releasever updates
baseurl=http://download.fedoralegacy.org/redhat/$releasever/updates/$basearch
gpgcheck=1

[legacy-utils]
name=Fedora Legacy utilities for Red Hat Linux $releasever
baseurl=http://download.fedoralegacy.org/redhat/$releasever/legacy-utils/$basearch
gpgcheck=1