can't install curl

I am writing:

sudo apt-get install curl --fix-missing

This is the output:

Reading package lists... Done Building dependency tree

Reading state information... Done The following NEW packages will be installed: curl 0 upgraded, 1 newly installed, 0 to remove and 13 not upgraded. Need to get 179 kB of archives. After this operation, 373 kB of additional disk space will be used. WARNING: The following packages cannot be authenticated! curl Install these packages without verification [y/N]? y Err http://ift.tt/u86xTH natty-updates/main curl i386 7.21.3-1ubuntu1.2 404 Not Found [IP: 91.189.88.149 80] Err http://ift.tt/unqOyP natty-security/main curl i386 7.21.3-1ubuntu1.2 404 Not Found [IP: 91.189.92.201 80] Failed to fetch http://ift.tt/1LX88s7 404 Not Found [IP: 91.189.92.201 80] E: Internal Error, ordering was unable to handle the media swap

Linux mint 11 Rosinka