If you ask me what should you do if you want you never got check it by invisible checker, then I will answer in 1 years ago there no way you can avoid being checked it by invisible checker. But now, I believe, I found a new ways to protect our self from being checked it by such invisible status detector. Yes, We can block invisible status checker by using Yahoo Messenger Alias ID.
We knew that Alias ID (not main ID) can be set to active and inactive. When Alias ID inactive it would like Dead ID and the invisible checker would mark it as offline ID. So just use Alias ID as your main chat ID, and then feel free to inactive or activate it.
Instead of invisible using invisible status, inactive ID would make better protection for us. Including for boot attack and invisible checker.
How to use Alias aka Secondary Public ID as your main Chat ID and protect block Invisible Status Detector you can read it here.