Read in your post : How to install mate desktop environment in Sparkylinux : " ... In the case of wheezy the backports repository has to be enabled as described in the official backport documentation...".
I must confess I didn't check the official backport documentation (by the way, a link would appreciated ... thanks !). I just added these two lines in my "/apt/sources.list" which are :http://ftp.us.debia.org/debian/
wheezy-backports main non-free contrib &&http://ftp.us.debia.org/debian/
wheezy-backports main non-free contrib (Code Source)
Did you do that to get the backports open ?
P.S. : Looks like it works ! From my terminal :
sudo update-pepperflashplugin-nonfree --status
Flash Player version installed on this system : 184.108.40.206
Flash Player version available on upstream site: 220.127.116.11
Thanks a lot .. I'm gonna try it now by using Google-Chrome.