unfortunately I was able to reproduce this behavior in each and every newly created VI in LV2013 x64 I created since I found out about it. My first guess actually was a corrupted control, so I tried it with another scalar control next to the "offending" one, which, I seem to remember, changed to an array as I expected. After that I tried to figure out what was causing the trouble resulting in the screenshots I posted. In time I decided to try and restart LabVIEW in the hope something got messed up, and yes, there came a window about some DWARN messages after exiting LabVIEW, which I, if truth be told, receive from time to time - I stopped worrying about those.
But after I restarted LabVIEW, NO control whatsoever did me the favour of turning into an array ever since. Not even when I replaced the possibly messed up copies in my LV2013 x64-QD-folder with the original one from this very thread.
Again, I repeat - I had been working with this great shortcut since its release, on this very same computer (and on others). It is highly unlikely that I would have never, in all this time, used it for turning a control into an array in x64 before some days ago, when I became aware of this oddity.
This being said, I really think it must be something about my LV installation that's causing it and most likely nothing about the programming of the shortcut or indeed LabVIEW itself.
If it really is a problem with the installation, I think you should repair your install. Sure it will take a while, but who knows what other problems may crop up later if there is a core file that is corrupted or otherwise problematic?