[exim] Incorrect password during exim test.

Hi,

I have corrected some problem with testing error exim 4.42 by
reinstalling cyrus-imap2.01 and cyrus-sasl.
I used cyradm add user sam to the sasldb.db file, then use saslpasswd -c
sam created its password.
But running exim test according to the follownig reference is failed:
http://www.munk.nu/exim/exim-freebsd-asmtp.php

The first test witih cyrus-iimap failed:
]# imtest -a sam -m login -p imap localhost
C: C01 CAPABILITY
S: * OK at.authtec.com Cyrus IMAP4 v2.0.17 server ready
S: * CAPABILITY IMAP4 IMAP4rev1 ACL QUOTA LITERAL+ NAMESPACE UIDPLUS ID
NO_ATOMIC_RENAME UNSELECT MULTIAPPEND SORT THREAD=ORDEREDSUBJECT
THREAD=REFERENCES IDLE STARTTLS AUTH=DIGEST-MD5 AUTH=CRAM-MD5
S: C01 OK Completed
Password:
C: L01 LOGIN sam {4}
+ go ahead
C: <omitted>
L01 NO Login failed: cannot connect to pwcheck server
Authentication failed. generic failure
Security strength factor: 0

The screen dump of the exim test is as follow:
SMTP>> 250-at.authtec.com Hello localhost [127.0.0.1]
250-SIZE 52428800
250-PIPELINING
250-AUTH PLAIN LOGIN
250 HELP
AUTH PLAIN AHNhbQB0ZXN0
SMTP<< AUTH PLAIN AHNhbQB0ZXN0
Running pwcheck authentication for user "sam"
pwcheck: access denied (Incorrect password)
plain authenticator:
$1 =
$2 = sam
$3 = test
expanded string: 0
SMTP>> 535 Incorrect authentication data
535 Incorrect authentication data

I think there is a problem with pwcheck. I just checked the running 
process of it, made sure it is running:
# ps -auxww | grep pwch
root     63801  0.0  0.1  1348  848  ??  Is    8:13PM   0:00.01 
/usr/local/sbin/pwcheck

Can anyone tell me how to trace and correct this error?

Thanks very much
Sam