A while back I filed a bug on this. Got a response from Apple:
This is a follow up to Bug ID# 5894285. After further investigation it has been determined that this is a known issue, which is currently being investigated by engineering. This issue has been filed in our bug database under the original Bug ID# 5242204. The original bug number being used to track this duplicate issue can be found in the State column, in this format: Duplicate/OrigBug#. So it sounds like Apple is already aware of the problem and is working on it. I guess that's good news. CB
