[Solved] forum table not updated when a new topic is posted

I am encountering a strange problem I never had before with any Drupal install, which is the following : when I post a new topic in a forum, it's not displayed in the topic list. At the same time, the forum list has a proper post count and last post is properly displayed. Also the new topics are properly listed as published in admin/content/node and I can access them fine.

I run Drupal 6.10 and I have no extra access modules installed, except Organic Groups Access since I have Organic Groups set up. I have two containers set, one called "Public" for public forums, and one is "Extranet" for OG forums (this container is set as group forum container in admin/og/og_forum).

I checked permissions for the forum, comment and taxonomy modules. I checked the node_access table for those topics (they belong to the realm : all -> seems OK to me). Then I checked the forum vocabulary is in the vocabulary_node_types table -> it is. I then checked that those post where referenced in the term_node table -> they are.

I finally found out that the problem is that the forum table is not updated when I create a new post. I was able to confirm it's the source of the problem by manually inserting nid, vid, tid for of a bunch of topics in the forum table. Those immediately showed up in the appropriate forums.

The million dollar question is, why would the forum module not update the forum table when I create a topic ?

I have given a look at modules/forum/forum.module to understand the logic but I can't seem to see where things could have gone wrong.

Anyone has an idea or has encountered the same issue ?

Thanks !