Cannot install m2release plugin

[Andreas Schöneck]

Hey there,

whenever I try to install m2release plugin into Hudson 2.2.0 (with maven plugin 2.2.1) I get an HTTP 500 error with a stack trace beginning as follows

java.lang.NullPointerException
	at hudson.model.UpdateSite$Plugin.getNeededDependencies(UpdateSite.java:580)
	at hudson.model.UpdateSite$Plugin.deploy(UpdateSite.java:622)
	at hudson.PluginManager.doInstall(PluginManager.java:539)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

If I drop the hpi manually the output differs a little bit:

Feb 28, 2012 5:02:23 PM hudson.model.Hudson
SEVERE: Failed Initializing plugin m2release
java.lang.NullPointerException
	at hudson.PluginManager$2$1$2.run(PluginManager.java:313)
	at org.jvnet.hudson.reactor.TaskGraphBuilder$TaskImpl.run(TaskGraphBuilder.java:146)
	at org.jvnet.hudson.reactor.Reactor.runTask(Reactor.java:259)
	at hudson.model.Hudson$4.runTask(Hudson.java:698)
	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.runWorker(ThreadPoolExecutor.java:1110)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
	at java.lang.Thread.run(Thread.java:722)

Feb 28, 2012 5:02:23 PM hudson.model.Hudson
INFO: Prepared all plugins
Feb 28, 2012 5:02:13 PM hudson.model.Hudson
SEVERE: Failed Loading plugin m2release
java.io.IOException: Dependency javadoc (1.0) doesn't exist
	at hudson.PluginWrapper.resolvePluginDependencies(PluginWrapper.java:443)
	at hudson.PluginManager$2$1$1.run(PluginManager.java:296)
	at org.jvnet.hudson.reactor.TaskGraphBuilder$TaskImpl.run(TaskGraphBuilder.java:146)
	at org.jvnet.hudson.reactor.Reactor.runTask(Reactor.java:259)
	at hudson.model.Hudson$4.runTask(Hudson.java:698)
	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.runWorker(ThreadPoolExecutor.java:1110)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
	at java.lang.Thread.run(Thread.java:722)


What can I do to circumvent or solve this? Or is the error rather related to some bugs in Hudson that are already fixed in Jenkins?
Any other ideas?

Thanks in advance and regards
Andreas