BB codes stop working in posts intermittently

[libertate]

I have asked vB, but unfortunately, I have not received a solution from them.

For some reason, in some threads, specifically in one forum (Articles), the BB codes in the posts do not get translated, after some unknown event. That is all the brackets with the codes are displayed.

The BB codes would work for a day, or a week, then suddenly just appear as text.

I cannot tag it to a time event, or posting, because this has happened at any time of the day with no changes to the threads in question.

I have disabled all plug-ins before, and the result is the same.

If I go into the BBCode settings under admincp, and just resave a BB code without any changes, the translation works.

It might be related to a specific cron job, but cannot figure which would touch the DB to corrupt it. I ran some of them, but no results.

The current plug-ins are Advanced BBCode Permissions, Archive Adsense, Commbull, Limited Guest Viewing, Miserable Users, vBadvanced CMPS, vbBannerRotator by Frapegliko, and vBSEO :: Sitemap Generator.

I use the default template, with style modifications.

I would love to hear some ideas, or solutions on how to fix this!