The site went offline some time ago, and right before it did, I have received a comment reply.
I could only read that comment reply after the site came back online. But now it won't go away, even though the thread in which the comment exists was deleted (by the owner).
This means that whenever I open a new page (or even hit refresh) the red mark notifying me of a comment reply is back, with the same comment.
[Technical details: Arch Linux, 64bit, Firefox 29.0.1]
Related Meta.SE threads: