memcached dropped connections: Rebalance failed due to replicator_died: exited (ns_single_vbucket_mover)

Failing test is:-
rebalancetests.RebalanceInOutWithParallelLoad.test_load,get-logs:True,replica:2,num_nodes:7

[ns_server:info] [2012-05-21 8:17:31] [ns_1@10.1.3.109:<0.15105.17>:ns_replicas_builder:kill_a_bunch_of_tap_names:209] Killed the following tap names on 'ns_1@10.1.3.109': [<<"replication_building_62_'ns_1@10.1.3.112'">>]
[ns_server:info] [2012-05-21 8:17:31] [ns_1@10.1.3.109:<0.15104.17>:ns_single_vbucket_mover:mover_inner:88] Got exit message (parent is <0.13796.17>). Exiting...
{'EXIT',<0.15105.17>,{replicator_died,{'EXIT',<16541.21868.10>,normal}}}
[ns_server:error] [2012-05-21 8:17:31] [ns_1@10.1.3.109:<0.15104.17>:ns_replicas_builder:sync_shutdown_many:147] Shutdown of the following failed: [{<0.15105.17>,
                                    {replicator_died,
                                     {'EXIT',<16541.21868.10>,normal}}}]
[error_logger:error] [2012-05-21 8:17:31] [ns_1@10.1.3.109:error_logger:ale_error_logger_handler:log_report:72]
=========================CRASH REPORT=========================
  crasher:
    initial call: erlang:apply/2
    pid: <0.15105.17>
    registered_name: []
    exception exit: {replicator_died,{'EXIT',<16541.21868.10>,normal}}
      in function ns_replicas_builder:'-build_replicas_main/6-fun-0-'/1
      in call from ns_replicas_builder:observe_wait_all_done_tail/5
      in call from ns_replicas_builder:observe_wait_all_done/5
      in call from ns_replicas_builder:'-build_replicas_main/6-fun-1-'/8
      in call from ns_replicas_builder:try_with_maybe_ignorant_after/2
      in call from ns_replicas_builder:build_replicas_main/6
    ancestors: [<0.15104.17>,<0.13796.17>,<0.13763.17>]
    messages: [{'EXIT',<16541.21868.10>,normal}]
    links: [<0.15104.17>]
    dictionary: []
    trap_exit: true
    status: running
    heap_size: 121393
    stack_size: 24
    reductions: 12423
  neighbours:

[ns_server:error] [2012-05-21 8:17:31] [ns_1@10.1.3.109:<0.15104.17>:ns_replicas_builder:try_with_maybe_ignorant_after:68] Eating exception from ignorant after-block:
{error,{badmatch,[{<0.15105.17>,
                   {replicator_died,{'EXIT',<16541.21868.10>,normal}}}]},
       [{ns_replicas_builder,sync_shutdown_many,1},
        {ns_replicas_builder,try_with_maybe_ignorant_after,2},
        {ns_single_vbucket_mover,mover,6},
        {proc_lib,init_p_do_apply,3}]}
[rebalance:error] [2012-05-21 8:17:31] [ns_1@10.1.3.109:<0.13796.17>:ns_vbucket_mover:handle_info:158] <0.15104.17> exited with {exited,
                             {'EXIT',<0.15105.17>,
                                 {replicator_died,
                                     {'EXIT',<16541.21868.10>,normal}}}}
[ns_server:info] [2012-05-21 8:17:31] [ns_1@10.1.3.109:<0.9348.1>:ns_port_server:log:161] memcached<0.9348.1>: TAP (Producer) eq_tapq:rebalance_61 - Schedule the backfill for vbucket 61
memcached<0.9348.1>: TAP (Producer) eq_tapq:rebalance_61 - Sending TAP_OPAQUE with command "opaque_enable_auto_nack" and vbucket 0
memcached<0.9348.1>: TAP (Producer) eq_tapq:rebalance_61 - Sending TAP_OPAQUE with command "enable_checkpoint_sync" and vbucket 0
memcached<0.9348.1>: TAP (Producer) eq_tapq:rebalance_61 - Sending TAP_VBUCKET_SET with vbucket 61 and state "pending"
memcached<0.9348.1>: TAP (Producer) eq_tapq:rebalance_61 - Sending TAP_OPAQUE with command "initial_vbucket_stream" and vbucket 61
memcached<0.9348.1>: TAP (Producer) eq_tapq:rebalance_61 - Backfill is completed with VBuckets 61,
memcached<0.9348.1>: TAP (Producer) eq_tapq:rebalance_61 - Sending TAP_OPAQUE with command "close_backfill" and vbucket 61
memcached<0.9348.1>: Vbucket <61> is going dead.
memcached<0.9348.1>: TAP (Producer) eq_tapq:rebalance_61 - Sending TAP_VBUCKET_SET with vbucket 61 and state "active"
memcached<0.9348.1>: TAP takeover is completed. Disconnecting tap stream <eq_tapq:rebalance_61>
memcached<0.9348.1>: TAP (Producer) eq_tapq:replication_building_62_'ns_1@10.1.3.112' - Schedule the backfill for vbucket 62
memcached<0.9348.1>: TAP (Producer) eq_tapq:replication_building_62_'ns_1@10.1.3.112' - Sending TAP_OPAQUE with command "opaque_enable_auto_nack" and vbucket 0
memcached<0.9348.1>: TAP (Producer) eq_tapq:replication_building_62_'ns_1@10.1.3.112' - Sending TAP_OPAQUE with command "enable_checkpoint_sync" and vbucket 0
memcached<0.9348.1>: TAP (Producer) eq_tapq:replication_building_62_'ns_1@10.1.3.112' - Sending TAP_OPAQUE with command "initial_vbucket_stream" and vbucket 62

[error_logger:error] [2012-05-21 8:17:31] [ns_1@10.1.3.109:error_logger:ale_error_logger_handler:log_report:72]
=========================CRASH REPORT=========================
  crasher:
    initial call: ns_single_vbucket_mover:mover/6
    pid: <0.15104.17>
    registered_name: []
    exception exit: {exited,
                        {'EXIT',<0.15105.17>,
                            {replicator_died,
                                {'EXIT',<16541.21868.10>,normal}}}}
      in function ns_single_vbucket_mover:mover_inner/6
      in call from ns_replicas_builder:try_with_maybe_ignorant_after/2
      in call from ns_single_vbucket_mover:mover/6
    ancestors: [<0.13796.17>,<0.13763.17>]
    messages: []
    links: [<0.13796.17>]
    dictionary: [{cleanup_list,[<0.15105.17>]}]
    trap_exit: true
    status: running
    heap_size: 987
    stack_size: 24
    reductions: 4014