For some reason the Body/Excerpt are not being Textiled after approving an article in mem_moderation_article. It appears to be down to two factors (or perhaps user error :-)
the array_merge() in mem_article_approver() is overwriting the 'textile_body' and 'textile_excerpt' keys with ones from the inbound $data array, as per the array_merge rules (later keys overwrite earlier ones of the same name).
the 2nd parameter in include/txp_article.php's textile_main_fields() function is called $use_textile but doesn't actually do anything of the sort. It does nothing in fact. The incoming data stream is the only thing that is used to determine whether to textile something or not.
I have worked around these issues by using the construct given in the attached file, from line 565 of mem_article_approver(). A longer term, better solution would be preferred, as would investigation into why the core has a function with a bogus unused parameter, and txp_article.php contains 5 references to global $txpcfg and uses none of them!