I get the following stack trace when I attempt to launch a new slave that does not have Java installed. I have added my username and password for the JDK Installer using Manage Jenkins.

Linux UbuntuDesktop9 2.6.32-32-generic #62-Ubuntu SMP Wed Apr 20 21:52:38 UTC 2011 x86_64 GNU/Linux
Installing JDK jdk-6u16-oth-JPR@CDS-CDS_Developer
Downloading JDK from http://download.oracle.com/otn/java/jdk/6u16-b01//jdk-6u16-linux-x64.bin
ERROR: Unexpected error in launching a slave. This is probably a bug in Jenkins.
java.lang.AssertionError: class hudson.plugins.sshslaves.SSHLauncher$DefaultJDKInstaller is missing its descriptor
at jenkins.model.Jenkins.getDescriptorOrDie(Jenkins.java:1074)
at hudson.tools.ToolInstaller.getDescriptor(ToolInstaller.java:125)
at hudson.tools.JDKInstaller.getDescriptor(JDKInstaller.java:588)
at hudson.tools.JDKInstaller.locate(JDKInstaller.java:360)
at hudson.plugins.sshslaves.SSHLauncher.attemptToInstallJDK(SSHLauncher.java:345)
at hudson.plugins.sshslaves.SSHLauncher.resolveJava(SSHLauncher.java:282)
at hudson.plugins.sshslaves.SSHLauncher.launch(SSHLauncher.java:234)
at hudson.slaves.SlaveComputer$1.call(SlaveComputer.java:199)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
at java.util.concurrent.FutureTask.run(FutureTask.java:138)
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)