Can't start Jenkins 1.462 because of the following error on Java 5.

SEVERE: Failed to initialize Jenkins
java.lang.UnsupportedClassVersionError: Bad version number in .class file (unable to load class com.google.common.collect.ImmutableSet)
at org.apache.catalina.loader.WebappClassLoader.findClassInternal(WebappClassLoader.java:2822)
at org.apache.catalina.loader.WebappClassLoader.findClass(WebappClassLoader.java:1159)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1647)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1526)
at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:320)
at hudson.security.PermissionScope.<init>(PermissionScope.java:70)
at hudson.security.PermissionScope.<clinit>(PermissionScope.java:95)
at hudson.security.Permission.<init>(Permission.java:179)
at hudson.security.Permission.<clinit>(Permission.java:292)
at jenkins.model.Jenkins.<clinit>(Jenkins.java:3817)
at hudson.WebAppMain.installLogger(WebAppMain.java:256)
at hudson.WebAppMain.contextInitialized(WebAppMain.java:107)
at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4206)
at org.apache.catalina.core.StandardContext.start(StandardContext.java:4705)
at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:799)
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:779)
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:601)
at org.apache.catalina.startup.HostConfig.deployDescriptor(HostConfig.java:675)
at org.apache.catalina.startup.HostConfig.deployDescriptors(HostConfig.java:601)
at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:502)
at org.apache.catalina.startup.HostConfig.start(HostConfig.java:1317)
at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:324)
at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:142)
at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1065)
at org.apache.catalina.core.StandardHost.start(StandardHost.java:840)
at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1057)
at org.apache.catalina.core.StandardEngine.start(StandardEngine.java:463)
at org.apache.catalina.core.StandardService.start(StandardService.java:525)
at org.apache.catalina.core.StandardServer.start(StandardServer.java:754)
at org.apache.catalina.startup.Catalina.start(Catalina.java:595)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:592)
at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:289)
at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:414)
May 2, 2012 12:30:44 PM org.apache.catalina.core.StandardContext start
SEVERE: Error listenerStart
May 2, 2012 12:30:44 PM org.apache.catalina.core.StandardContext start
SEVERE: Context [/hudson] startup failed due to previous errors

Reverting to 1.461 solve the issue.