assertion error in offheap bloom filter

 INFO [CompactionExecutor:2] 2012-11-08 09:35:18,206 CompactionTask.java (line 116) Compacting [SSTableReader(path='/tmp/dtest-n2D_fM/test/node2/data/system/local/system-local-ia-9-Data.db'), SSTableReader(path='/tmp/dtest-n2D_fM/test/node2/data/system/local/system-local-ia-11-Data.db'), SSTableReader(path='/tmp/dtest-n2D_fM/test/node2/data/system/local/system-local-ia-10-Data.db'), SSTableReader(path='/tmp/dtest-n2D_fM/test/node2/data/system/local/system-local-ia-13-Data.db')]
ERROR [CompactionExecutor:2] 2012-11-08 09:35:18,257 CassandraDaemon.java (line 132) Exception in thread Thread[CompactionExecutor:2,1,main]
java.lang.AssertionError: Memory was freed
    at org.apache.cassandra.io.util.Memory.checkPosition(Memory.java:134)
    at org.apache.cassandra.io.util.Memory.getByte(Memory.java:104)
    at org.apache.cassandra.utils.obs.OffHeapBitSet.get(OffHeapBitSet.java:60)
    at org.apache.cassandra.utils.BloomFilter.isPresent(BloomFilter.java:71)
    at org.apache.cassandra.db.compaction.CompactionController.shouldPurge(CompactionController.java:106)
    at org.apache.cassandra.db.compaction.PrecompactedRow.removeDeletedAndOldShards(PrecompactedRow.java:64)
    at org.apache.cassandra.db.compaction.PrecompactedRow.<init>(PrecompactedRow.java:95)
    at org.apache.cassandra.db.compaction.CompactionController.getCompactedRow(CompactionController.java:151)
    at org.apache.cassandra.db.compaction.CompactionIterable$Reducer.getReduced(CompactionIterable.java:72)
    at org.apache.cassandra.db.compaction.CompactionIterable$Reducer.getReduced(CompactionIterable.java:57)
    at org.apache.cassandra.utils.MergeIterator$ManyToOne.consume(MergeIterator.java:114)
    at org.apache.cassandra.utils.MergeIterator$ManyToOne.computeNext(MergeIterator.java:97)
    at com.google.common.collect.AbstractIterator.tryToComputeNext(AbstractIterator.java:143)
    at com.google.common.collect.AbstractIterator.hasNext(AbstractIterator.java:138)
    at com.google.common.collect.Iterators$8.computeNext(Iterators.java:734)
    at com.google.common.collect.AbstractIterator.tryToComputeNext(AbstractIterator.java:143)
    at com.google.common.collect.AbstractIterator.hasNext(AbstractIterator.java:138)
    at org.apache.cassandra.db.compaction.CompactionTask.runWith(CompactionTask.java:146)
    at org.apache.cassandra.io.util.DiskAwareRunnable.runMayThrow(DiskAwareRunnable.java:48)
    at org.apache.cassandra.utils.WrappedRunnable.run(WrappedRunnable.java:28)
    at org.apache.cassandra.db.compaction.CompactionTask.execute(CompactionTask.java:69)
    at org.apache.cassandra.db.compaction.CompactionManager$BackgroundCompactionTask.run(CompactionManager.java:179)
    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)