I have been using TouchPal Keyboard it works great in both portrait and landscape. I use it on all my devices it is nice to have one keyboard across tablet and phone.
I've been using SwiftKey since I got the HD+ and hybrid rooted it. When the newest update came through, I 'unrooted,' but SwiftKey still worked great. Maybe you need to uninstall and reinstall it. Did you get it through Play or the Nook Apps?