I would like to offer a suggestion. While not an extremely common occurrence, I do come across very old threads that have been dredged up from the dim past by someone posting in it. It is rather confusing when, all of a sudden, there is a multi-page thread that has materialized out of nowhere and is filled with posts by people who are no longer participants or those you have never heard of. As a solution I would like to suggest using a vB plugin like this one. It is used on the forum I admin on and it really helps keep down the confusion caused by resurrected threads. The duration before a thread is automatically closed can be set to whatever you want, and special threads (stickied and such) can be excluded. If someone wants to discuss the topic of an old thread they can start a new one and link to the old one if needed. Again, just a suggestion as this is a pet peeve of mine.