[vps-mail] IS0-8859 spams slipping by SpamAssassin

["Jim Smith" <maillists@xxxxxxxxxxxxxxxx>]

I get spam with "prescription" in the subject or body, spelled in a variety
of ways such as this: "Your prescrip@tion delivered to your house by
tomorrow". Ok, I set up a series of SA rules to score it higher such as this
one that should catch the above spam: 

describe PRESCRIP_MUNGED_8      Prescription is Misspelled
full   PRESCRIP_MUNGED_8       /prescrip.tion/i
score    PRESCRIP_MUNGED_8        2.1

The problem is that the message gets through. I click on the headers and,
instead of seeing the subject, "Your prescrip@tion delivered to your house
by tomorrow", I see this:

Subject:
=?ISO-8859-1?b?WW91ciBwcmVzY3JpcEB0aW9uIGRlbGl2ZXJlZCB0byB5b3VyIGhvdXNlIGJ5I
HRvbW9ycm93IQ==?=

I've tried to find a pattern in these headers but I can't figure it out and
can't find references on how to handle the IS0-8859 headers. 

Any suggestions for creating rules for this IS0-8859 stuff?

Thanks,

Jim Smith
 
 --------------------------------------------------------
           Jim Smith, Blarneystone, LLC.
  Website Design, Hosting, Development & Enhancement
   E-MAIL:      jimsmith@xxxxxxxxxxxxxxxx
   WEBSITE:     http://www.blarneystone.com
 --------------------------------------------------------

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