You pretty much know when you can't PM them. That means they're ignoring you on the board, too.

I try to remember that not everyone will agree with me even if I JUST KNOW that what I have to say works. I put it out there and if it's usefull, fine. If not, oh, well!

Some people just aren't ready to move from where they are or are in denial that they have or cause a problem. Nothing you can do until they're ready.