sstable2json error

/apache-cassandra-1.1.1/bin> ./sstable2json /home/cassandra/data/pimda/CF_bookmark/pimda-CF_bookmark-hd-48-Data.db > test.json

ERROR 22:27:14,215 Error in ThreadPoolExecutor
java.lang.ClassCastException: java.math.BigInteger cannot be cast to java.nio.ByteBuffer
at org.apache.cassandra.db.marshal.UTF8Type.compare(UTF8Type.java:27)
at org.apache.cassandra.dht.LocalToken.compareTo(LocalToken.java:45)
at org.apache.cassandra.db.DecoratedKey.compareTo(DecoratedKey.java:89)
at org.apache.cassandra.db.DecoratedKey.compareTo(DecoratedKey.java:38)
at java.util.TreeMap.getEntry(TreeMap.java:328)
at java.util.TreeMap.containsKey(TreeMap.java:209)
at java.util.TreeSet.contains(TreeSet.java:217)
at org.apache.cassandra.io.sstable.SSTableReader.load(SSTableReader.java:396)
at org.apache.cassandra.io.sstable.SSTableReader.open(SSTableReader.java:187)
at org.apache.cassandra.io.sstable.SSTableReader$1.run(SSTableReader.java:225)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:441)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
at java.util.concurrent.FutureTask.run(FutureTask.java:138)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:662)
ERROR 22:27:14,219 Error in ThreadPoolExecutor
java.lang.ClassCastException: java.math.BigInteger cannot be cast to java.nio.ByteBuffer
at org.apache.cassandra.db.marshal.UTF8Type.compare(UTF8Type.java:27)
at org.apache.cassandra.dht.LocalToken.compareTo(LocalToken.java:45)
at org.apache.cassandra.db.DecoratedKey.compareTo(DecoratedKey.java:89)
at org.apache.cassandra.db.DecoratedKey.compareTo(DecoratedKey.java:38)