Can not allow Greenshot to upload screenshots directly to my account on Imgur

When I try to upload screenshot to Imgur, window pops up and ask me to autorize greenshot. I type my login and pass and click "allow" button, and get 403 error, I tried to open the same link in IE and do the same, and it went successful, but greenshot still wont upload my screenshots.
Here's images of the window:
http://i.imgur.com/r9rgH3V.png
http://i.imgur.com/r9rgH3V.png