To be able to write to an ntfs partition, you need the ntfs-3g kernel module loaded. That module comes with OpenSuse 10.3. So, make sure it is loaded (lsmod in a terminal to see the loaded modules; modprobe to load it if it isn't currently loaded).
You also need write permission for the ntfs partition. If the user/group of the partition is root/root, you will not be able to write to the partition. You would have to change the user/group to root/user (owner is root; group is user), then make sure that your user name is in the user group. Also make sure that the user group has write permission for the partition.
chgrp user /media/disk # to change the group to user.
groupadd -A <username> <group> # where username is your user name, and group is the group to add the user name into (in this case, the group is user). The command becomes: groupadd -A <username> user.
To add write permission, chmod g+w /media/disk # to give the group members write permission.
I'm the sole user of the comp, and work as root.
Not a good idea. You are setting yourself up for a lot of heartache.