Comment 9 for bug 653630

I've just marked bug 742930 as a duplicate of this but, based on comparing the stack traces. That bug had three duplicates of its own which are now duplicates of this bug: bug 753268, bug 753712, and bug 756805. In the (I think) unlikely event that bug 742930 is determined not really to be a duplicate of this bug, those three bugs should be considered to be unmarked as duplicates of this bug too (and perhaps remarked as duplicates of bug 742930).