I have a custom cursor that works fine in most browsers. In firefox however, the parts that don’t have 100% alpha turns black. As far as I can understand, Firefox is suppose to support alpha in cursor images.
https://developer.mozilla.org/en/SVG/Element/cursor
sample page(hoover the image):
http://dev.nuagency.se/illustrators/beata-boucht-2/
The image:
http://dev.nuagency.se/wp-content/themes/nuagency/images/left.png
Alpha-layers in cursors just was not supported in firefox, nothing to do about it.