Thinking along some lines of how to improve it.
I guess the PHP accelerator could act as a SSI page.
Each forum row gets cached seperately.
And the PHP would be something like
if (in_array($f, $hidearray) == FALSE) {
include("./$cache_path/forum_summary/Forumrow$f");
}
that could work without putting too much of a strain on the server.
Not sure how it would work on the non-php side though.
Thoughts?