Owen is correct that
HADOOP-5203 is a solution for this issue. However, it was committed only to trunk, after the 0.20 branch point. Therefore, v0.21 and higher have it, but v0.20 and its derivatives, including v1.0, does not. The fix needs to be ported to branch-1.
I am reopening and re-titling this jira for the port work, since
HADOOP-5203 is closed.