I had trouble with SUSE ftp install too. All I can say is to find out a few mirrors and their IPs (I was told that the installer can't resolve URLs to IPs). I got the same error as you and if I remember correctly (well it's been many days now
I just had to choose another mirror and hope that they work.
One hint for future, when installing software with YAST it sometimes tells you that a spesific package doesn't exist on the mirror you are using. It apparently is just because YAST has lost connection to the mirror or something like that, just click Abort and then from the main YAST window Accept. YAST then installs the remaining packages.