We have had confirmation from Apple that this was an OSX bug and should be fixed in the latest Mountain Lion update. However no word from Apple as to whether they have already put the fix into Lion.
From Apple:
We believe this issue has been addressed in OS X Mountain Lion 10.8.2. The GM
version is available now. Please verify this issue and update your bug report
with the results.
OS X 10.8.2 build 12C54
Posted Date: September 19, 2012
http://support.apple.com/kb/DL1581
Wim