As a simple fix I changed reset to use setFaviconTag instead of Tinycon.setImage. The best fix would be to reset the canvas and go back to using setImage.
make reset use setFaviconTag instead of setImage
Still doesn't work in firefox, fixes it for webkit though.
I just tested in Firefox (14,15,16 mac and 16 win) and it works just fine.
Thanks @cwardzala all merged in