Spam scores don't add up

[Gerry Doris]

I was just checking the spam scores of a message and noticed that they
aren't adding up correctly.  If you check the header shown below it
comes out to a total of 5.76 but the actual score is 8.2.  Any idea why???

snip....
X-MailScanner: Found to be clean
X-MailScanner-SpamCheck: spam, SpamAssassin (score=8.2, required 4, AWL 0.00,
        BAYES_80 2.86, MIME_BOUND_MANY_HEX 2.90, UPPERCASE_75_100 0.00)

                        EL-GORDO SWEEPSTAKE INTERNATIONAL LOTTERY NL.
            BURDENSTRAAT 22 1053 DS, AMSTERDAM.THE            NETHERLANDS
snip....

--
Gerry

"The lyfe so short, the craft so long to learne"  Chaucer