Auto Unlock LUKS drives ...now no boot

[Curious Anomaly]

Hi folks,

I have just installed Ubuntu 8.04 from the Alternate CD, making a number of encrypted partitions in the process. All was fine on boot except for needing to type a password for each encrypted partition, so next stop was this page to automate it...
http://howtoforge.com/automatically-...with-a-keyfile

Step 3 kept failing with a "no Luks device" message. I tried numerous different paths for /dev/sdX but same problem each time. Then I opened a second terminal window and it did work. I completed the instructions but step 6 didn't seem to do anything and on reboot, I get multiple copies of this message...
"Command failed: No key available with this passphrase"
...followed by a whole load of (one for each encrypted partition)...
"No such file or directory while trying to open /dev/mapper/sdaX_crypt"


1) How can I revert the system to try the automation setup again?
2) If I want to move the keyfile onto a USB stick, what do I need to do?

Thanks in advance for any help.