Resurecting/Posting in old threads
This is a touchy subject here on AF. Sometimes its OK, other times you could be banned.
If its a thread older than one month and it is not your thread, do not post a reply. PM the person that started the thread to see if they are still intrested in the topic, or could possibly answer your question.
Never bring up a post more than a few months old, except for one circumstance. If it is your thread, and you have updates then it is ok to post the updates and bring it up to the top, but do NOT bump it, the thread will be locked or deleted. Remember, only if its a few months old, and its your thread and you have updates you can bring it up. Otherwise start a new thread.
NEVER EVER Bring up a thread that is more than one year old. Start a new thread.
Its a touchy subject. Sometimes its OK, other times is wrong. Use your best judgement.