It is possible that it sold or was brought down by the owner and then he wiped the Title and thread info. The thread still exists, but it will have the title of (for instance) "Sold" with the first thread only reading "Sold".
Ár skal rísa, sá er annars vill
fé eða fjör hafa. Sjaldan liggjandi úlfur
lær um getur né sofandi maður sigur.