I think Align implimentation is yet another work in progress!
It may not help you in this situation but I have a keyboard shortcut set up for artboard-fit-to-selected, I select just the items I need to align, hit the shortcut, and use the align on artboard setting.
(I have the full document set up with a keyline, I select that, then hit the shortcut again to get back to the full size artboard.)
I use this a lot for zooming around a document too.
The first image you are distributing to a key object and that seems to have worked correctly. Not sure what is going on in the second image, definitely not working for horizontal alignement to the artboard. Did resetting preferences work?