different results unsing feTurbulence between inkscape and firefox

When writing out a png file with inkscape --export-png the following code will produce different results then what is seen and expected in firefox.

Something seems to function strangely with regard to the baseFrequency of feTurbulence. it has a very narrow window of change.
values of 0.1 to 0.0001 produce relatively similar results compared with their representation in the web browser.

values close to 0.1 yield similar results, however using lower values such as 0.001 produce two very different outcomes.

In addition, adding the 'primitiveUnits' parameter to the filter seems to result in no filter being applied.

  ( <filter id="L2" x="0" y="0" width="100%" height="100%" primitiveUnits="objectBoundingBox" > )

I'm running: Inkscape 0.91 r13725 (Jul 19 2015)
platform: Mac OSX 10.10.5

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
    <svg height="300" width="300" viewBox="0 0 300 300" >
        <defs>
            <filter id="F1" x="0" y="0" width="100%" height="100%" >
                <feTurbulence baseFrequency="0.01" numOctaves="1" type="turbulence" seed="1" stitchTiles="stitch" result="noise" />
            </filter>
        </defs>
        <rect x="0" y="0" width="300" height="300" rx="0" ry="0" stroke="#000" stroke-width="0.3" fill="#646464" opacity="1" filter="url(#F1)" />
    </svg>