I've just found Inkscape while searching for editors. What a great editor!

I apologize in advance for this question because I think this is a bug in Adobe SVG Viewer.

If I import a raster image with a unicode filename like test_Глава.jpg, I can view the resulting svg in Inkscape and Firefox. However viewing it in Adove SVG embedded in Internet Explorer does not show the image. Is this a bug in Adobe? Is ther any way to work around it by encoding the filename? I have tried to manually url encode the filename in the href with no luck.

If the character encoding was wrong then I wouldn't expect Inkscape or Firefox to display it - so it's probably correct and there's a bug with Adobe SVG viewer.

I don't think the Adobe SVG viewer is maintained now Adobe owns Flash so your only alternative would be to trip away special characters.

Note that I'm not an expert in this area--I'm making assumptions that could be wrong.