Super key permanently disabled in keyboard shortcuts

I see this maybe once a month. Ubuntu 14.04.1 AMD64 Desktop (and previous versions) spontaneously disable all of my Super+(letter) keyboard shortcuts which activate certain apps from the launcher. The shortcuts are still showing in the All Settings, Keyboard menu. I even attempt to reset them. Nothing works. However, I can change the shortcut to avoid Super and it will work, e.g. Super+N changes to Ctrl+Shift+N.

This always seems to happen during the boot process. In other words, I don't think it spontaneously occurs during a live OS context, but I'm not totally sure.

The only way to fix it is an OS reinstall. If we at least had a workaround better than I've noted above, that would be useful.

This even happened on an isolated machine which was working fine and broke spontaneously despite having been disconnected from the net since the initial install.

Generally, it also seems like Ubuntu gets confused between Super meaning "open the launcher" and Super meaning "please wait a few deciseconds for me to hit my magic letter". Maybe we Super just simply shouldn't be allowed for keyboard shortcuts at all. Better yet, let us easily configure the key used to make the launcher appear. Many users never want to deal with it at all, as it just covers the left side and adds latency to the interface.