If you have a password protected image (a password required to boot, not just restricted) then lilo -R imagename will prompt at boot time for the image password, then time out and boot the default image. This makes it impossible to boot into a password protected image unless you're at the console. Here's a sample of what I use (sorry for the line wrapping) image=/boot/vmlinuz.reinstall optional password=XXXXX initrd=/boot/initrd.reinstall label=reinstall read-only append="lang= devfs=nomount ks=nfs:server.name.invalid:/usr/local/kickstart/ks.cfg" Without the "password" line I can initiate a remote upgrade with lilo -R reinstall; reboot but of course I have to password protect this image.
This is unfortunately a limitation of the way that password mode works in lilo. You can remove the timeout section from your lilo.conf and you won't have to worry about it timing out in the future, although then it won't ever boot into the default without human intervention.