strange spam mail

[Eric Persson]

Hello everyone,

I query the knowledge of this list from time to time when I'm 
experiencing difficulties with bogofilter. Often you solve those 
questions easily, but this time I'm really puzzled.

I've started recieving some spam that bogofilter doesnt seem to handle 
well. And I have recieved about 1000 similar mails, when I've trained bf 
  with the first say 500 I would guess the rest should be marked as 
spam, but it isnt.

As an example I have put 3 of the mails on the net for you to see, with 
the resulting x-bogosity line below:
http://files.persson.tm/documents/mail/Illegal%20Content%20Violation%20-%20Message%2097607.txt
X-Bogosity: No, tests=bogofilter, spamicity=0.926449, version=0.16.0
http://files.persson.tm/documents/mail/Illegal%20Content%20Violation%20-%20Message%204703.txt
X-Bogosity: No, tests=bogofilter, spamicity=0.000293, version=0.16.0
http://files.persson.tm/documents/mail/Extreme%20Content%20Violation%20-%20Message%2073119.txt
X-Bogosity: No, tests=bogofilter, spamicity=0.863759, version=0.16.0

I score the mail with the following command through a .qmail file
/usr/bin/bogofilter -H -p -C -d 
/webmail/8/4/84deda69dc38c4a39443e9b7a8230018/bogofilter/

My understanding of what bf really does is somewhat limited, I just now 
it used to work well, and still works quite well, but with this 
particular type of spam it seems to fail. I'm a bit curios why, and is 
there something I can do to stop it? :)

Best regards and keep up the good work!
	Eric