postdata_presave hook

[Carnage]

I've been using the postdata_presave hook to log posts to an xml file for training a spam filter with, however for some reason none of the spam posts seem to have been logged. This is highly confusing as I was under the impression that EVERY post had to hit the postdata_presave hook at some point.

Is there a better hook to use to catch all posts before they are saved to the database?

EDIT:

Ughhh. It would seem that someone somewhere hates good code design... there are infact two main methods for posts to get into the db... apparently there is a need to treat a post separatly if its the first post in a thead :s