Can't figure out how to use Code Per Node

Hi,

I'm trying to install and use Code Per Node, bit can't seem to figure out how it's working. I'm running a Drupal 6.19 installation. I've installed Code Per Node 6.x-1.2 and CodeMirror 1.0. I also had CKEditor installed, but disabled it, just in case it was in conflict. The attached cpn-edit-screenshot shows you what my editor currently looks like. I tried putting a sample CSS in the body field, but it's just treated as normal text.

Code Per Node is installed here:

.../sites/all/modules/CONTRIB

CodeMirror is installed here:

.../sites/all/libraries/codemirror

However, although both appear to be installed, I don't seem to be able to use it. When I try to edit a node, I expect to see fields for custom CSS and custom Javascript as pictured here:

http://drupal.org/node/1017690

However, I don't see such fields.

Here are the steps I've taken to install/configure

1. Install CodeMirror to ../sites/all/libraries/codemirror -- check!

2. Turn on syntax highlighting at ../admin/settings/cpn -- check!

See cpn-admin screenshot.

3. Set appropriate permissions at ../admin/user/permissions -- check!

See cpn-permissions screenshot. I'm an administrator

4. Enable per-content type settings at admin/content/node-type/[node-type]

According to the notes:

Code per content type has not been back ported for D6.

...so I've not done this.

5. Enable Code Per Node at ../admin/build/modules -- check!

6. Clear Drupal cache (by clicking button “Clear cached data.” ) at .../admin/settings/performance -- check!