After yum update that downloaded and installed 1.460 the following shows in jenkins.log
Apr 15, 2012 9:03:54 PM winstone.Logger logInternal
SEVERE: Error initializing web application: prefix []
java.io.FileNotFoundException: /var/cache/jenkins/war/META-INF/MANIFEST.MF (No such file or directory)
at java.io.FileOutputStream.open(Native Method)
.. etc..
and Jenkins does not start.
The directory /var/cache/jenkins/ is empty
Running mkdir /var/cache/jenkins/war; cd /var/cache/jenkins/war; jar -xvf /usr/lib/jenkins/jenkins.war; chmod a+w ./
and restarting jenkins via the /etc/inid.d/jenkins script works.