My blog gets hundreds, if not thousands, of spam trackbacks per day. They are usually caught by the antispam filters, but they clog the system anyway. This is normal behaviour, I fear.
What it is not normal is that I am getting spam trackback for posts where trackback is disabled. I have a script which disables them one week after I posted the entry:

update mt_entry set entry_allow_pings = 0 where DATE_SUB(CURDATE(),INTERVAL 7 DAY) >= entry_created_on AND entry_allow_pings = 1;

Indeed, if I look at the old entries, the box "accept trackbacks" is not checked. But - as I wrote - trackback keep coming anyway.
Is there something I forgot? I am running MT4.1.