I see. The tutorial tells you to dupe the other area node, which has No Center set and it doesn't tell you to turn it off. I believe I tried this as well but turning it off doesn't seem to update the preview, it just stays off.
I ran into a few problems trying to turn it off, actually. Every time the program crashed with an error
Start new project
Add an image node.
Add an area node to that.
Set the No Center on.
Duplicate the area node.
Turn off No Center in the new node for an immediate crash.
I managed to sort it out by manually editing the xml, thanks for your help and the work you've done on this.