With notify-osd, "low disk space" notifications become spam

Binary package hint: gnome-settings-daemon

When a mounted volume becomes low on disk space, something -- notify-osd claims it's gnome-settings-daemon -- pops up a notification to tell the user.
Under the old notification daemon, this would pop up as a bubble, once per minute; these bubbles use both timeouts and actions, I believe.
Under the new notify-osd, these notifications instead pop up as background dialogs, and remain open indefinitely. So, after using the computer for about 7 minutes, you end up with a cluttered taskbar... and as time goes on, these windows will group together into a single button, "notify-osd (37)" -- that is, 37 of those windows.

The bug here is that the notification pops up multiple times, and then stays open each time. It should either pop up only once or twice, or it should be a standard bubble -- and the latter option will likely still be irritating. Additionally, for non-critical (i.e. not home or root) directories, it should only reappear when the amount of free space changes.

notify-osd: 0.9.14.1-0ubuntu1
gnome-settings-daemon: 2.27.3-0ubuntu2