How come my avatar isn't transparent?

Here's where I got the original from: Render

When I open it in gimp, it's already transparent but when I upload it as my avatar, it still has that white space behind it. What gives? :|

 

It needs to be saved in .png format with a transparent background.

 

Tried that, is there a certain setting I have to use when saving it?

 

you need to save it as .png, and then resize it in GIMP and save as .png

Make sure there is no BACKGROUND layer

 

.PNG is the best format for those things, try saving the file in that format