I tried the solution exposed here :
http://www.suseforums.net/index.php?showtopic=48185
But to no avail so i tried the solution indicated by WJM :
Code:
cd /var/cache/zypp
mv zypp.db /root/zypp.db
zypper refresh
And that worked...
Thank you for your help...
What caused my problem ?
Is this a known bug ?