OG Seems to Largely Ignore OG_ABT Module

I have quite a simple set-up, just 2 group types. It is essential that members of groups in Group Type A can only post into their own specific group AND groups OF TYPE B! Put simply, members of groups in Group Type A want to show their projects to members of groups of Type B but other groups of Type A are competitors and so they do not want them to see their projects.
I have been into Group Type A (content type) "OG Audience Settings" and have ticked the "omit from audience targetting system" box for the content type "Project". I have been into Group Type B and have ticked nothing except those roles I would like to be able to post into groups they do not belong to for the content type "Project".
However, neither groups of Type A nor Type B show up on the Audience Selector box when creating a node (nor when editing it). The Project is simply posted automatically into the group for which the poster is a member (of Type A).
Furthermore, in the "Project" content type I have restricted access to the "Public" checkbox to only the Administrator and yet this still appears for all users. In all, the OG-ABT module seems to be completely ignored.

The only way it seems possible to get it to work is to subscribe the members of Groups Type A to be members of Groups Type B also OR to give the posting members of Groups Type A permission to ADMINISTER NODES which defeats the purpose as it allows them to see Projects from other Groups of Type A.

Am I doing something wrong? The functionality of this module is perfect for what I want if I could just get it to work.

If you wish to recreate:
Drupal 6.12
Both Group Types are CLOSED and are LISTED IN GROUPS DIRECTORY
ORGANIC GROUPS CONFIG > GROUP DETAILS > AUDIENCE CHECKBOXES is ticked
ORGANIC GROUPS ACCESS CONFIG > VISIBILITY OF POSTS > VISIBILITY CHOSEN BY ...DEFAULTS TO PRIVATE is selected
ORGANIC GROUPS ABT is enabled (but not ABT DOMAIN)
CONTENT TYPE "Project" (ie NOT the Group node) OG AUDIENCE SETTINGS > PUBLIC PUBLISHING ACCESS > CHIEF ADMIN only (ie NOT the member posting the "Project")
CONTENT TYPE "Group Type A" (ie the groups from which Projects will be published) > OG AUD. SETTINGS > PROJECT > OMIT FROM AUD. TARGETTING SYSTEM is ticked
CONTENT TYPE "Group Type B" (ie groups into which I would like members of "A" groups to be able to publish) > OG AUD. SETTINGS > PROJECT > user roles of publishing members of Groups Type A are highlighted.

Sorry hope this isnt too much detail.