What kernel version are you using? You must have that or it will not be able to read the partitions. Just as a additional note, If you make your root partition use ext3, then you must have it compiled IN the kernel, NOT as a module.
It has to be there somewhere. It's on the first menu in the 2.6 kernel, not sure where it is in the 2.4 kernel. It's been a while since I saw one of those.