It sometimes happens, that upon fresh start of tomcat, not all Jobs/Projects are loaded.
Once logging in and clicking on "reload configuration from disk" this works w/o any error and all the missing jobs are there.
It seems to be random... and on another restart some other jobs are missing...
Any clue?

INFO: Started all plugins
Dec 16, 2011 9:14:36 AM jenkins.InitReactorRunner$1 onAttained
INFO: Augmented all extensions
Dec 16, 2011 9:14:59 AM jenkins.InitReactorRunner$1 onTaskFailed
SEVERE: Failed Loading job XXXXXX
java.lang.NoClassDefFoundError: hudson/plugins/analysis/core/AbstractProjectAction
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClassCond(ClassLoader.java:632)
at java.lang.ClassLoader.defineClass(ClassLoader.java:616)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:141)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:283)
at java.net.URLClassLoader.access$000(URLClassLoader.java:58)
at java.net.URLClassLoader$1.run(URLClassLoader.java:197)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
at java.lang.ClassLoader.loadClass(ClassLoader.java:248)
at hudson.plugins.checkstyle.CheckStylePublisher.getProjectAction(CheckStylePublisher.java:128)
at hudson.tasks.BuildStepCompatibilityLayer.getProjectActions(BuildStepCompatibilityLayer.java:73)
at hudson.model.Project.createTransientActions(Project.java:208)
at hudson.model.AbstractProject.updateTransientActions(AbstractProject.java:602)
at hudson.model.AbstractProject.onLoad(AbstractProject.java:272)
at hudson.model.Project.onLoad(Project.java:88)
at hudson.model.Items.load(Items.java:115)
at jenkins.model.Jenkins$14.run(Jenkins.java:2364)
at org.jvnet.hudson.reactor.TaskGraphBuilder$TaskImpl.run(TaskGraphBuilder.java:146)
at org.jvnet.hudson.reactor.Reactor.runTask(Reactor.java:259)
at jenkins.model.Jenkins$5.runTask(Jenkins.java:804)
at org.jvnet.hudson.reactor.Reactor$2.run(Reactor.java:187)
at org.jvnet.hudson.reactor.Reactor$Node.run(Reactor.java:94)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:662)
Caused by: java.lang.ClassNotFoundException: hudson.plugins.analysis.core.AbstractProjectAction
at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
at java.lang.ClassLoader.loadClass(ClassLoader.java:248)
... 27 more
Dec 16, 2011 9:15:19 AM jenkins.InitReactorRunner$1 onAttained
INFO: Loaded all jobs
Dec 16, 2011 9:15:19 AM jenkins.InitReactorRunner$1 onAttained
INFO: Completed initialization