I've just installed the new version 1.5.2 over the recent 18.104.22.168 and wrote something about it:
I included three trackbacks in this article - but they don't work. Normally when I wrote an article and viewed it in the admin-mode I have an area below of the "user defined fields" called "already pinged articles" where I can see the trackback-URLs.
But when I am looking into the admin mode of the new article I can't see the "already pinged"-section - instead of it the trackback-URLs can be found in the section "send trackbacks to".
So I must assume, that the trackback isn't running now. And the only thing I have changed recently was to update to 1.5.3. Could this be the reason?