FTP update of SuSE-8.0 failed to update the base package

I first made boot.iso. Then, tried to update from 7.3 to 8.0 by ftp. Yast2 came up nicely. After normal selections for updating, I realized that the install procedure does not allow updating the base package. Only the non-base packages have been updated. As you can imagine, when the machine booted up, it still showed up SuSE-7.3. I went back and tried to find what I missed. Nothing. The box for updating base package is indicated "no", and I cannot modify that selection. Regards, Hugh