As part of a hardware upgrade, I ghosted my slackware 10.2 distro from hda3 on the old system to hda4 on the new. Now, booting with either loadlin or a grub CD, I get a partial boot, then the error 'The reiserfs system block cannot be found on /dev/hda3. Failed to open the filesystem.

Note it says hda3, not 4. Fsck from a Knoppix CD shows a good file system at /dev/hda4, and reiserfsck --rebuild-sb /dev/hda4 did not solve the problem.

Here are my grub commands:

root (hd0,3) [grub finds the file system after this command]
kernel /boot/vmlinuz root=/dev/hda4 ro [again, grub is satisfied]
boot

Is there some config file still pointing at hda3, that I could edit with Knoppix to fix the problem?

did you fix the /etc/fstab file?

Doh! Thanks, that fixed it.