[kh99]

I'm not completely sure if I know what's going on in the code, or if I get what you're asking, but I think there's different kinds of caching going on. One is to cache results during the processing of a page so that work isn't repeated, like parsing the same signatures over and over in the a thread. Then there's the post cache that survives between user requests. So I think that 'cachable' field in class_bbcode might be for caching signatures during one page request but not between (different users') requests. (I know this doesn't really help you solve your problem).