[Dovecot] Deliver die if global sieve script turn on

[M1]

In my installation "deliver" die if global sieve script turn on. Is there 
anything I have missed? Thanks..

Flex 2.5.33
Dovecot 1.0.rc29
postfix 2.3.8

In maillog:
Apr  3 13:29:58 minigrass postfix/pipe[24691]: CA194121BC5: to=<[EMAIL 
PROTECTED]>, 
relay=dovecot, delay=0.24, delays=0.14/0.01/0/0.09
, dsn=5.3.0, status=bounced (Command died with status 
2: "/usr/libexec/dovecot/deliver". Command output: input in flex scanner 
failed )

In master.cf :
dovecot         unix    -       n       n       -       -       pipe
        flags=DRhu user=dovecot:dovecot argv=/usr/libexec/dovecot/deliver -d 
${recipient} -n

in dovecot.conf:
  mail_plugins = cmusieve quota
  global_script_path = /home/mail/sieve/global

in /home/mail/sieve/global/dspam.sieve
require "fileinto";
        if header :is ""X-DSPAM-Result" "Spam" {
                fileinto "Spam";
        }

Regards