Everything is easy as long as you know how... Hmmmm, that sounds like something that Yogi would say... I will spare you the agony... Sense I don't use Inkscape, it took me a couple hours to figure this one out. FZ told you wrong... When you save your .svg, don't save it as Plain SVG... save it as Optimized SVG and check the boxes in the dialog box that will pop-up "Convert CSS Attributes to XML Attributes" which will convert your style properties to XML attributes, 
and "Remove Metadata" which will remove a bunch of unneeded stuff that clutters up your file. The rest of the check boxes I am not sure about or if any of them need to be checked for FZ.
This will cost you a brownie button... 
only got one all last week... and I made a bunch of parts... 