I've seen this several times today. When the jboss-as-5 plugin tried to connect to a remote AS 6.0.0.M1 instance, the remote call to ManagementView.load() sometimes throws an InterruptedException. Here's the stack trace:

java.lang.RuntimeException: java.lang.InterruptedException
at org.jboss.remoting.transport.socket.MicroSocketClientInvoker.transport(MicroSocketClientInvoker.java:823)
at org.jboss.remoting.MicroRemoteClientInvoker.invoke(MicroRemoteClientInvoker.java:167)
at org.jboss.remoting.Client.invoke(Client.java:1917)
at org.jboss.remoting.Client.invoke(Client.java:768)
at org.jboss.aspects.remoting.InvokeRemoteInterceptor.invoke(InvokeRemoteInterceptor.java:60)
at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102)
at org.jboss.aspects.remoting.MergeMetaDataInterceptor.invoke(MergeMetaDataInterceptor.java:74)
at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102)
at org.jboss.aspects.security.SecurityClientInterceptor.invoke(SecurityClientInterceptor.java:65)
at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102)
at org.jboss.aop.generatedproxies.AOPProxy$1.load(AOPProxy$1.java)

The AS6 server is running find with no issues. This is pretty serious from the RHQ/Jopr perspective, because it results in the AS6 instance to be incorrectly reported as being down.