upgrade fedora 19 to fedora 20 issue with GPG key

[Rafnews]

Hi,

before posting on this forum, i checked on internet for this issue and 
found several cause and solutions.
i tried several of them but till now none of them worked.

when i try to update fedora 19 to fedora 20 (/fedup --network 20/) i get 
the following error message:

    /finding updates 100%
   
[=======================================================================================================================================]//
    //verify local files 100%
   
[====================================================================================================================================]//
    //warning:
   
/var/tmp/system-upgrade/rpmfusion-free/packages/rpmfusion-free-release-20-1.noarch.rpm:
    Header V3 RSA/SHA256 Signature, key ID ae688223: NOKEY//
    //Importing GPG key 0xAE688223://
    // Userid     : "RPM Fusion free repository for Fedora (20)
    <rpmfusion-buildsys(a)lists.rpmfusion.org&gt;&quot;//
    // Fingerprint: 0017 ddfe fd13 2929 9d55 b1d3 963a 8848 ae68 8223//
    // Package    : rpmfusion-free-release-19-1.noarch (installed)//
    // From       : /etc/pki/rpm-gpg/RPM-GPG-KEY-rpmfusion-free-fedora-20//
    //
    //Downloading failed: Didn't install any keys/


i tried:
1. yum --enablerepo=updates-testing update fedup
but it didn't help

2. rpm --import /etc/pki/rpm-gpg/RPM-GPG-KEY-rpmfusion-nonfree-fedora-20
but it didn't help

3. fedup-cli --network 20 --nogpgcheck
install things and reboot with error. After complete restart, uname -a 
still shows fedora 19 as version of fedora :(

4. rpm -qi fedup
it returns:

/Name        : fedup//
//Version     : 0.8.0//
//Release     : 3.fc19//
//Architecture: noarch//
//Signature   : RSA/SHA256, jeu. 12 déc. 2013 16:22:34 CET, Key ID 
07477e65fb4b18e6//
//Source RPM  : fedup-0.8.0-3.fc19.src.rpm//
////
/so it is the latest version of fedup according to documentation.

therefore what is wrong ?
thx.