Run this test case in three window that we can all them as A, B, C. after starting all these tree, then stop C first and resart it quickly, then B, and A.

public class TestJoin {

public static final String DEFAULT_PROTOCOL_STACK=
"UDP(mcast_addr=228.8.8.8;mcast_port=45566;ip_ttl=32;mcast_send_buf_size=150000;" +
"mcast_recv_buf_size=80000):" +
"PING(timeout=2000;num_initial_members=2):MERGE2(min_interval=5000;max_interval=10000):" +
"FD_SOCK:" +
"FD(timeout=10000;max_tries=5;shun=true):" +
"VERIFY_SUSPECT(timeout=12500):" +
"pbcast.NAKACK(gc_lag=50;retransmit_timeout=300,600,1200,2400,4800;max_xmit_size=8192):" +
"UNICAST(timeout=300,600,1200,2400):pbcast.STABLE(desired_avg_gossip=20000):" +
"FRAG(frag_size=8096;down_thread=false;up_thread=false):" +
"pbcast.GMS(join_timeout=5000;join_retry_timeout=2000;shun=false;print_local_addr=false)";

public static void main(String[] args)
{
NotificationBus bus;
try

{ bus = new NotificationBus ( "test", DEFAULT_PROTOCOL_STACK ); bus.getChannel ().setOpt ( Channel.LOCAL, Boolean.FALSE ); bus.start (); }

catch (Exception e)

{ // TODO Auto-generated catch block e.printStackTrace(); }

while(true)
{
System.out.println("******************************************");
try

{ Thread.sleep(5000); }

catch (InterruptedException e)

{ // TODO Auto-generated catch block e.printStackTrace(); }

}
}
}

And after that, the A and B will be blocked for joining the group. here is hte console output:
(it should join the group and output the ****************)

2008-1-18 10:49:15 org.jgroups.JChannel init
Info: JGroups version: 2.6.1
2008-1-18 10:49:16 org.jgroups.protocols.pbcast.NAKACK setProperties
Warn: max_xmit_size was deprecated in 2.6 and will be ignored
2008-1-18 10:49:16 org.jgroups.stack.Protocol setPropertiesInternal
Warn: down_thread was deprecated and is ignored
2008-1-18 10:49:16 org.jgroups.stack.Protocol setPropertiesInternal
Warn: up_thread was deprecated and is ignored
2008-1-18 10:49:16 org.jgroups.protocols.pbcast.GMS setProperties
Warn: join_retry_timeout has been deprecated and its value will be ignored
2008-1-18 10:49:21 org.jgroups.protocols.pbcast.ClientGmsImpl join
Warn: join(10.70.148.165:1371) sent to 10.70.148.165:1350 timed out (after 5000 ms), retrying
2008-1-18 10:49:26 org.jgroups.protocols.pbcast.ClientGmsImpl join
Warn: join(10.70.148.165:1371) sent to 10.70.148.165:1350 timed out (after 5000 ms), retrying
2008-1-18 10:49:31 org.jgroups.protocols.pbcast.ClientGmsImpl join
Warn: join(10.70.148.165:1371) sent to 10.70.148.165:1350 timed out (after 5000 ms), retrying
2008-1-18 10:49:36 org.jgroups.protocols.pbcast.ClientGmsImpl join
Warn: join(10.70.148.165:1371) sent to 10.70.148.165:1350 timed out (after 5000 ms), retrying
2008-1-18 10:49:41 org.jgroups.protocols.pbcast.ClientGmsImpl join
Warn: join(10.70.148.165:1371) sent to 10.70.148.165:1350 timed out (after 5000 ms), retrying
2008-1-18 10:49:46 org.jgroups.protocols.pbcast.ClientGmsImpl join
Warn: join(10.70.148.165:1371) sent to 10.70.148.165:1350 timed out (after 5000 ms), retrying

I have used Jgroups 2.2.9, and the same problem happened (different console output with more message trace information.).