[Reeve of shinra]

I'm not familiar with the mod but there are other hacks (like the journal and photopost and vbgallery, and maybe a few others) that work in a similiar way, they may have an answer to your issue.

If anything, I think the plug in is using a hook that is only called up for threads, not announcements. You may need to add the code to a new plugin using the correct hook, or changing the hook location to global. The later may have a performance hit on your forums so use with care.