Steps to reproduce
1) Create a scheduled operation to call 'Get Info On All Plugins' from an agent resource
2) shutdown the agent which has the operation scheduled
3) When the operation is scheduled to execute you get the following sort of exception in the console

14:38:30,656 INFO [JobRunShell] Job rhq-resource-502551.rhq-resource-502551-1399531558-1215727830953 threw a JobExecutionEx
ception:
org.quartz.JobExecutionException: Failed to execute scheduled operation [ResourceOperationSchedule: resource=[Resource[id=50
2551, type=RHQ Agent, key=LENOVO-A4A86477 RHQ Agent, name=LENOVO-A4A86477 RHQ Agent, version=1.0.1.GA]],job-name=[rhq-resour
ce-502551-1399531558-1215727830953], job-group=[rhq-resource-502551], operation-name=[retrieveAllPluginInfo], subject=[org.r
hq.core.domain.auth.Subject[id=2,name=rhqadmin]], description=[]] [See nested exception: org.jboss.remoting.CannotConnectExc
eption: Can not get connection to server. Problem establishing socket connection for InvokerLocator [socket://127.0.0.1:1616
3/?backlog=200&clientMaxPoolSize=304&enableTcpNoDelay=true&maxPoolSize=303&numAcceptThreads=1&rhq.communications.connector.r
hqtype=agent&socketTimeout=60000]]
        at org.rhq.enterprise.server.operation.ResourceOperationJob.execute(ResourceOperationJob.java:88)
        at org.quartz.core.JobRunShell.run(JobRunShell.java:203)
        at org.quartz.simpl.SimpleThreadPool$WorkerThread.run(SimpleThreadPool.java:520)
* Nested Exception (Underlying Cause) ---------------
org.jboss.remoting.CannotConnectException: Can not get connection to server. Problem establishing socket connection for Invo
kerLocator [socket://127.0.0.1:16163/?backlog=200&clientMaxPoolSize=304&enableTcpNoDelay=true&maxPoolSize=303&numAcceptThrea
ds=1&rhq.communications.connector.rhqtype=agent&socketTimeout=60000]
        at org.jboss.remoting.transport.socket.MicroSocketClientInvoker.transport(MicroSocketClientInvoker.java:530)
        at org.jboss.remoting.MicroRemoteClientInvoker.invoke(MicroRemoteClientInvoker.java:122)
        at org.jboss.remoting.Client.invoke(Client.java:1550)
        at org.jboss.remoting.Client.invoke(Client.java:530)
        at org.rhq.enterprise.communications.command.client.JBossRemotingRemoteCommunicator.send(JBossRemotingRemoteCommunic
ator.java:385)
        at org.rhq.enterprise.communications.command.client.AbstractCommandClient.invoke(AbstractCommandClient.java:143)
        at org.rhq.enterprise.communications.command.client.ClientCommandSender.send(ClientCommandSender.java:996)
        at org.rhq.enterprise.communications.command.client.ClientCommandSenderTask.send(ClientCommandSenderTask.java:223)
        at org.rhq.enterprise.communications.command.client.ClientCommandSenderTask.call(ClientCommandSenderTask.java:108)
        at org.rhq.enterprise.communications.command.client.ClientCommandSenderTask.call(ClientCommandSenderTask.java:52)
        at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:269)
        at java.util.concurrent.FutureTask.run(FutureTask.java:123)
        at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:650)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:675)
        at java.lang.Thread.run(Thread.java:595)
Caused by: java.net.ConnectException: Connection refused: connect
        at java.net.PlainSocketImpl.socketConnect(Native Method)
        at java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:333)
        at java.net.PlainSocketImpl.connectToAddress(PlainSocketImpl.java:195)
        at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:182)
        at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:366)
        at java.net.Socket.connect(Socket.java:520)
        at org.jboss.remoting.transport.socket.SocketClientInvoker.createSocket(SocketClientInvoker.java:187)
        at org.jboss.remoting.transport.socket.MicroSocketClientInvoker.getConnection(MicroSocketClientInvoker.java:801)
        at org.jboss.remoting.transport.socket.MicroSocketClientInvoker.transport(MicroSocketClientInvoker.java:526)
        ... 14 more

Without the scheduled operation you just getting the following in the log when the agent is down

21:05:56,875 WARN [AgentManagerBean] Have not heard from agent [LENOVO-A4A86477] since [2008-07-21 21:02:37.39]. Will be ba
ckfilled since we suspect it is down