Via YOU, you can only update to security/bugfixes of the same version. You could try to set the option 'passive_ftp = on' in /etc/wgetrc to get this running, otherwise download the patch rpm from the server and update 'by hand'.
To install a 2.6 kernel on a SuSE 9.0 system, you will nedd to update the package module_init_tools and/or mkinitrd first (I am not sure, which was obligatory and I don't think that suse provides these packages anymore.) If you have installed these updates, then you may try to install a kernel of the day or the kernel of 9.1. You'll also need to create the /etc/modprobe.conf, since it replaces modules.conf. You could use a script that comes with the module_init_tools package
/sbin/generate-modprobe.conf > /etc/modprobe.conf
When you installed 9.1, not the kernel screwed your partition table, the tool parted did, and you could fix this, if you read here: