I think that newsposts are a special subscription, and will always display the full entry.

To get newsposts to respect the cut like a normal entry, hmm, probably the best option is to unsubscribe to news announcements, and then subscribe to all entries posted in dw_news via the profile page.

And to always see the full entry in your inbox, without a cut, uncheck the "Cut tag in inbox" option over in http://www.dreamwidth.org/manage/settings/?cat=display *g*