If I restart the jenkins service I receive this error in the log

Running from: /usr/share/jenkins/jenkins.war
[Winstone 2011/12/22 12:05:27] - Beginning extraction from war file
[Winstone 2011/12/22 12:05:27] - Container startup failed
java.lang.NullPointerException
at winstone.Launcher.shutdown(Launcher.java:353)
at winstone.Launcher.<init>(Launcher.java:220)
at winstone.Launcher.main(Launcher.java:398)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:616)
at Main._main(Main.java:268)
at Main.main(Main.java:96)

Sometimes an upgrade to a newer version will fix the problem temporarily, but eventually the service will stop working and I can't fix it until a new version of jenkins comes out.