I face the following strange issue: when using any of the Stack Exchange sites the toolbar icons do not show up:
When I inspect the DOM i see the sprites have not been loaded sucessfully:
If I follow the link there it will open just fine in a new tab.
Peeking into the Network tab reveals Firefox is not even trying to download the images:
I'm using Firefox 33.1 on OS X.
Is this a bug in Firefox? It seems related to using SVG, if I edit the CSS style and change the image to PNG format it will display just fine.
Why is Stack Exchange using SVG for this sprite and PNG for all the rest?