Any idea why the MOD appears to be trying to pass a header after the headers have already been passed?
check your modifications in posting.php : be careful if you have other MOD's installed which modified the functions prepare_post() and submit_post()
AFAIK, I don't have any other mods that have changed those, but I'll check again.
UPDATE: I have removed the MOD for now, and I'll check and see if I can find the conflict(s). Morpheus, if you want a list of the MOD's I was running along with this one that modify those functions, I'll be happy to post it here.