Thread Subject: doubt "nwalign" function

I am using the "nwalign" function of matlab R2007a to do global alignment. I use the example on P21 from the book Biological sequence analysis bu R. Durbin.
Below is my code:
****************************************************
A = 'HEAGAWGHEE';
B = 'PAWHEAE';
ScoringMatrixValue = 'BLOSUM50';

[Score, Alignment] = nwalign(A, B, 'Alphabet', 'AA', 'ScoringMatrix', ScoringMatrixValue,'GapOpen', 8, 'ExtendGap', 8,'Showscore', true);
****************************************************
The result is:
Score = 0.3333

Alignment =
HEAGAWGHE-E
    || || |
--P-AW-HEAE

My question is the Alignment is right (the same as in the book), but why the Score is 0.3333? You can easily calculate the alignment score,which should be 1 as shown in the book.

Is there something wrong with the function "nwalign"??