Since moving to Twitter's (now mandatory) oAuth authentication process, Snapatar hasn't been working very well. Images failed to upload for some users, while it worked for others. We need to address these issues before we put Snapatar back online.
Unfortunately, it seems there are a lot of unresolved problems with Twitter's API, oAuth and image uploads. For Snapatar to work, we need to be able to upload your newly snapped images reliably. We're looking into this, but for the time being, Snapatar won't be here to help you quickly update your Twitter profile image.