Occasionally it appears not to stick, but when you come back a day later the ignore is in effect.
I think it's something to do with the inability of Yahoo to find its own #$%$ with both hands.
Or because they use separate machines to composite portions of your experience on a single page. The ignore database is on one machine and the view enabling is on another and when you say to ignore it gets put in the database but then the view enabling uses an old cached copy and won't refresh to the newest data...or something. Eventually it catches up.
I think Diva means she's been using it to no avail.
The same thing happened to me yesterday.
I tried to "vacuum off" my AGNC board yesterday and the names did not disappear.
I did it numerous times, and then tried starting first with an abuse complaint, doing that numerous times as well..
Today my board is as clean as a whistle.