I really can't help you with you last question. The reason is, when I first viewed that tutorial many many months ago, I noticed that it had the warning that it was buggy and it could or would cause problems that may conflict with your first forum. For that reason, I never touched it.
My team and I are working on SSO (single sign on) with open source forum software. We are a few weeks away from a demo product. When it is up for demo, I will broadcast a message to all members over at http://skins4ning.com.
I have viewed you post's asking for help on this. I think when ning responds that this is an issue that cannot be fixed. You can be assured that it can't be fixed.
I noticed you said that you saw it working on other sites. I think the sites that have it working, are the ones that had purchased scripts from scripts4ning.ning.com. Ning now controls the scripts from this site and would be the ones you need to talk to, when trying to solve this issue.