We had a discussion earlier about a posting about Eat Sleep Race being missed by the ESR group. I turned off the "friend-purchase-content" flag and it's still showing stuff they purchase. Another issue is that on triples, the "Frequency of updates" drop down list appear waaaaay on the left screen.
The news section works like a feed, so any "news" you got in the past will remain on it. (Until it gets burried.) Mind the actual wording: "Notify when a friend purchases new content". Up until now you wanted to get notified, so you were. As soon as you untick this option you won't get notified anymore in the future, starting from the moment you unticked it.