Actually it isn't transparant because Watchdog turned it into a JPEG. The GIF you posted originally was working all right.
To Watchdog and all the other requesters: please take care when rehosting avatars and putting them up in your profile. As an avatar maker, it's annoying when you tried your best to make someone a high-quality avatar, and then they spoil it by making it pixelated, untransparant or applying any other form of degradation.
If there's something not to your liking about it (for example, if you run an old version of Internet Explorer that doesn't support PNG transparancy), it's better to just ask the artist to fix it. They have the original vector file and all the proper art programs, so it's usually a 5-minute-job for them. Don't be shy to ask.