region server appearing twice on HBase Master page

[Ted Yu]

I noticed two lines for the same region server on HBase Master page:
X.com:60030    1268160765854    requests=0, regions=16, usedHeap=1068,
maxHeap=6127
X.com:60030    1268250726442    requests=21, regions=9, usedHeap=1258,
maxHeap=6127

I checked there is only one
org.apache.hadoop.hbase.regionserver.HRegionServer instance running on that
machine.

This is from region server log:

2010-03-10 13:25:38,157 ERROR [IPC Server handler 43 on 60020]
regionserver.HRegionServer(844):
org.apache.hadoop.hbase.NotServingRegionException: ruletable,,1268083966723
        at
org.apache.hadoop.hbase.regionserver.HRegionServer.getRegion(HRegionServer.java:2307)
        at
org.apache.hadoop.hbase.regionserver.HRegionServer.get(HRegionServer.java:1784)
        at sun.reflect.GeneratedMethodAccessor10.invoke(Unknown Source)
        at
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:597)
        at
org.apache.hadoop.hbase.ipc.HBaseRPC$Server.call(HBaseRPC.java:648)
        at
org.apache.hadoop.hbase.ipc.HBaseServer$Handler.run(HBaseServer.java:915)
2010-03-10 13:25:38,189 ERROR [IPC Server handler 0 on 60020]
regionserver.HRegionServer(844):
org.apache.hadoop.hbase.NotServingRegionException: ruletable,,1268083966723
        at
org.apache.hadoop.hbase.regionserver.HRegionServer.getRegion(HRegionServer.java:2307)
        at
org.apache.hadoop.hbase.regionserver.HRegionServer.get(HRegionServer.java:1784)
        at sun.reflect.GeneratedMethodAccessor10.invoke(Unknown Source)
        at
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:597)
        at
org.apache.hadoop.hbase.ipc.HBaseRPC$Server.call(HBaseRPC.java:648)
        at
org.apache.hadoop.hbase.ipc.HBaseServer$Handler.run(HBaseServer.java:915)

If you know how to troubleshoot, please share.