[vchkpw] smtp auth

[signo]

hello i've a problem with smtp auth

when i try to send an email i have always the message:
454 oops, unable to write pipe and I can't auth (#4.3.0)

SW:
qmail: 1.3
smtp-auth: qmail-smtpd-auth-0.31

telnet on port 25

Escape character is '^]'.
ehlo
220  -=NO UNSOLICITED BULK E-MAIL=- ESMTP
250- -=NO UNSOLICITED BULK E-MAIL=-
250-AUTH LOGIN CRAM-MD5 PLAIN
250-AUTH=LOGIN CRAM-MD5 PLAIN
250-PIPELINING
250 8BITMIME
auth login
334 VXNlcm5hbWU6
dGVzdEB0ZXN0LmNo
334 UGFzc3dvcmQ6
dGVzdHBhc3M=
454 oops, unable to write pipe and I can't auth (#4.3.0)
auth plain
334
AHRlc3RAdGVzdC5jaAB0ZXN0cGFzcw==
454 oops, unable to write pipe and I can't auth (#4.3.0)
auth CRAM-MD5
334 PDE0MTg5LjEwODI2Mzg5MjFAL2Jpbi9jaGVja3Zwdz4=
dGVzdEB0ZXN0LmNoIDRlNTE5YTIzZGQzNDBmZjJlMDRjMjkwMjFkODY1ZDNi
454 oops, unable to write pipe and I can't auth (#4.3.0)


qmail-smtp/run script:

#!/bin/sh
QMAILDUID=`id -u qmaild`
NOFILESGID=`id -g qmaild`
MAXSMTPD=`head -1 /var/qmail/control/concurrencyincoming`
if [ -z "$QMAILDUID" -o -z "$NOFILESGID" -o -z "$MAXSMTPD" ]; then
    echo QMAILDUID, NOFILESGID orMAXSMTPD is unset in
    echo /var/qmail/supervise/qmail-smtpd/run
    exit 1
fi
exec /usr/local/bin/softlimit -m 6000000 /usr/local/bin/tcpserver -v  -p -x /etc/tcp.smtp.cdb -c "$MAXSMTPD"  -u "$QMAILDUID" -g "$NOFILESGID" 0 25 /var/qmail/bin/qmail-smtpd /bin/checkvpw /bin/true Maildir 2>&1


can you help me?

bye

signo