SA Autolearn do not run

[admins]

Hi all

System: Debian 5 64bit
Spamassassin: 3.2.5
local.cf config:

use_bayes 1
bayes_auto_learn 1
use_bayes_rules 1
bayes_min_ham_num 10
bayes_min_spam_num 10
bayes_file_mode 0777
bayes_path /var/spool/spamassassin/bayes
bayes_journal_max_size 15000000
bayes_expiry_max_db_size 20000000
auto_learn_threshold_nonspam 2.0
bayes_auto_learn_threshold_spam 5.5

May the bayes autolearn do not run (I've learned SA manually with 500spams and 300hams)

Mailheader:

X-Spam-Flag:  	NO
X-Spam-Level:  	
X-Spam-Score:  	-2.599
X-Spam-Status:  	No, score=-2.599 tagged_above=-9999 required=4 tests=[BAYES_00=-2.599, HTML_MESSAGE=0.001, SPF_PASS=-0.001]

Has someone an idea why I haven't the entry in the mailheader like autolearn=spam?

Thanks
admins