going black is just occasionally, i guess after a lot of navigation trough pages. but for example, just now, i opened nelisquare in portrait, see in the feed that somebody commented on a checkin, tap to see the comment, then i move the n900 in landscape to write a comment with keyboard, but rotating show only a little part of the screen, actually a small rectangle on top left of the screen.
also i had another stolen mayorship notification that doesnt disappear
and noticed that notifications of somebody commenting on your checkin, disappear automatically without the need to tap on the red ballon and list of notification.