It's annoying how many "dead" threads have been revived as of late. Here are two possible solutions to reducing the number of them...
1) The occurance could be related to the forum's feature that displays "related" threads at the bottom of each page, even if the "related" threads happen to be months old. Perhaps this feature could just be disabled?
2) It might be better (though more difficult to set up) for the forum to generate an automated prompt when a poster is about to reply to a thread that is more than, say, a week old. "THIS THREAD IS XX DAYS OLD. ARE YOU SURE YOU WANT TO ADD A REPLY?" No offense to the thread necrophiliacs out there, but it seems the posts that revive dead threads are often low on the thought meter. It would be nice to force these folks to think for a second before resucitating.