401 -“无法验证您的身份(消息头被twitter拒绝)。“当你尝试上传图片的时候，你可以在TwitPic上上传图片。”

I'm using meltingice's API for TwitPic and when I try to upload a picture I get a 401 error with the message "Could not authenticate you (header rejected by twitter)". and when