Can you tell us what you are doing in a bit more detail? Does this fail for all repositories, or only some? You have checked that you are (still) authorized, I presume?
Are you using the same machine that you previously used? Is your ssh key for GiHub there?
Try it from the command line, and see if it works there.
Davis Mariotti skrev 2012-10-24 10.37:
> Very suddenly, I can no longer push my files over to github, doing the same exact steps as I had previously done, but now I get a message saying auth fail. wWhat should I do?
Assuming SSH: Check that Eclipse looks for SSH keys in the right location.