@Highway, @asasergio, After researching the code tab issue a little further... the code is supposed to be uploaded through either the Arduino or PICAXE compiler and downloader via shell command(s). At the present time, only PICAXE is able to use the upload feather in Fritzing and Arduino will not have the via shell command(s) feature until Arduino 1.0...
Ref: http://blog.fritzing.org/2010/07/06/experimental-program-window/