Sometimes I agree with scripter that the "don't post to me" request should be honored.
1. If it is on one thread and doesn't involve thread-jumping.
2. If the person continues to ping you.
3. If others in the discussion continue to ping both of you.
4. IF the person comments on any arguments you've raised or directs comments at you, but then does not ping you.
5. If your name is used in a post and you are not pinged.
I really try to follow the advice in my tagline. Unfortunately, there are many times it doesn't depend on me and last resorts such as "don't post to me" are issued.