Correct behaviour of feTurbulence + feDisplacementMap

Hi,

I created an SVG which uses feTurbulence and feDisplacementMap to create a
sponge like effect.

The SVG renders differently in Firefox compared to Opera and Inkscape.

I have reported this issue to the Firefox team and they are investigating.
See the bug report here:
https://bugzilla.mozilla.org/show_bug.cgi?id=584322

Can someone please clarify which behaviour is correct? Perhaps there should
be a test case for this.

thanks,
-- 
Harshad RJ
http://hrj.wikidot.com