SpamAssassin BAYES_99 problem

[George Breahna <sa...@top-consulting.net>]

I have a problem with a few of my users that have spanish usernames ( this
is the only difference I can think of )

In any case, here's the problem:

Sending a mail to george@domain.com generates a score of 0.1 and thus no
problems:

The performed tests are the following:

  0.0 HTML_MESSAGE           BODY: HTML included in message
  0.1 HTML_50_60             BODY: Message is 50% to 60% HTML

When sending the same, same message to: jose@domain.com, I get this:

  0.0 HTML_MESSAGE           BODY: HTML included in message
  9.0 BAYES_99               BODY: Bayesian spam probability is 99 to 100%
                             [score: 1.0000]
  0.1 HTML_50_60             BODY: Message is 50% to 60% HTML


What gives ? What triggers the bayesian sistem to assign 99% spam
probability to the same message but to a different username ?

Any clue is appreciated!