People, I have been struggling over the two methods - Update Profile Image and Update Background Image I am using EpiTwitter library. I am uploading GIFs, Twitter returns the expected result for update_profile_background_image but returns 401 for update_profile_image , but the image is not changed. Here are the headers catched from $apiObj->headers in my case while using the update_profile_background_image Array ( [Date] => Sat, 24 Apr 2010 17:51:36 GMT [Server] => hi [Status] => 200 OK [X-Transaction] => 1272131495-55190-23911 [ETag] => b6a421c01936f3547802ae6b59ee7ef3" [Last-Modified] => Sat, 24 Apr 2010 17:51:36 GMT [X-Runtime] => 0.13990 [Content-Type] => application/json; charset=utf-8 [Content-Length] => 1272 [Pragma] => no-cache [X-Revision] => DEV [Expires] => Tue, 31 Mar 1981 05:00:00 GMT [Cache-Control] => no-cache, no-store, must-revalidate, pre- check=0, post-check=0 [Set-Cookie] => ****REMOVED**** [Vary] => Accept-Encoding [Connection] => close ) and for update_profile_image - Array ( [Date] => Sat, 24 Apr 2010 17:57:58 GMT [Server] => hi [Status] => 401 Unauthorized [WWW-Authenticate] => Basic realm="Twitter API" [X-Runtime] => 0.02263 [Content-Type] => text/html; charset=utf-8 [Content-Length] => 152 [Cache-Control] => no-cache, max-age=300 [Set-Cookie] => ****REMOVED**** [Expires] => Sat, 24 Apr 2010 18:02:58 GMT [Vary] => Accept-Encoding [Connection] => close ) Can somebody help me out?