standalone="no" breaks some images

Created by: haarp

I'm using Scour to optimize UI elements in Firefox. On some files this appears to break.

Scour adds standalone="no" to the header. This makes the file unable to be opened in Viewnior. If used as a Firefox UI element, it also fails to render (curiously it works if opened by Firefox as a page)

I don't understand what standalone means in the context of SVGs, so I can't say if this is a valid bug.

The file in question: menu-check-black.svg.zip