I personally find the spamx is not sufficient to block trackback spam. My site receives ~ 2-3 trackbacks a day which link to various material which I cannot make mention of in the post or I get spamx'ed
I did have some luck with the
trackback validation hack in the past... may try it again.
-- destr0yr
"I love deadlines. I like the whooshing sound they make as they fly by." -- Douglas Adams