I just noticed that https://issues.apache.org/jira/browse/HADOOP-1883 (Adding versioning to Record I/O) has become https://issues.apache.org/jira/browse/HBASE-291, even though it has nothing to do with HBase (as far as I know). I think this may be because it mentions HBase in one of the comments. Not sure this is a problem since it is now closed, but it may be something to look out for with other issues.
Tom