It seems that there may have been a change in Launchpad (in line with Matt's comments in comment #1) that allows this to work with new bugs like bug 837960 but for the original bug linked to in the description this does not work.
It seems that there may have been a change in Launchpad (in line with Matt's comments in comment #1) that allows this to work with new bugs like bug 837960 but for the original bug linked to in the description this does not work.