Hmm...well, I guess one possibility is that the "search plugins" mod wouldn't find it if the problem code is in an included file. And if the code is in more than one plugin (or included by more than one) then you might not find it by disabling plugins one by one (or five by five). (Edit:...oh, unless you ultimately disabled them all, then I guess it should have gone away at some point).
Of course it could also just be that I'm wrong.
Yup, disabling hooks clears the problem just fine. Either manually or in the Admin CP. Disabling whole groups of products doesn't seem to do the trick, though. I can only assume its what's technically referred to as one of those weird thingys.
It is definitely from a plugin om the help_bbcodes_bbcode hook.
That isn't a very commonly used hook in mods in my experience- see how many plugins you have on that hook, I would be surprised if it is more than 1.
If it is one, the problem is one line 24 of that plugin.
Could not find a plugin that used that hook. In fact, only found one that even referenced a BB Code function at all, and it's been disabled for a while now. EDIT: Correction. I should do a search for "bbcode", as well as "bbcodes". [sigh] BRB