hmmmm. make sure you're pressing the save button under the choose file tab and also press the save button at the top right of the page next to the cancel button.

up in the top right corner of the screen is the little box with all your stats. click on the thing that says 'account'. then  click the blue button that says 'change avatar'. under the title ' actions' is a little icon that looks like a pencil and paper, click that. then choose the file you want to upload from your computer and save it.

cool