The ligature appears for me, but the font only seems to mess up in firefox. Which is weird, because i would have expected Firefox and IE to have the same behaviour owing to DirectWrite..(?)
http://imgur.com/a/HNH5H From top to bottom: Chrome 27/beta, Firefox 16, IE 10 on Windows 7 x64.
http://imgur.com/a/HNH5H From top to bottom: Chrome 27/beta, Firefox 16, IE 10 on Windows 7 x64.