IMAP connect problem, please help me.

[yk5515]

I often encounter this:

09-Jul-2010 01:46:36 +0000]: iil_C_Copy
[09-Jul-2010 01:46:36 +0000]: unknow imap connect info!
[09-Jul-2010 01:46:36 +0000]: array (
0 => '',
)
[09-Jul-2010 01:46:36 +0000]: http://www.testyk001.com/?_task=mail
[09-Jul-2010 01:46:36 +0000]: [email protected]
[09-Jul-2010 01:46:40 +0000]: Current IMAP connect number: 21, All connect number: 1109
VMSTAT:
procs -----------memory---------- ---swap-- -----io---- --system-- -----cpu------
r b swpd free buff cache si so bi bo in cs us sy id wa st
1 2 0 5641640 435048 9062240 0 0 26 34 1 0 3 1 93 3 0
IOSTAT:
Linux 2.6.18-164.15.1.el5PAE (hg01.testyk001.com) 07/08/10

avg-cpu: %user %nice %system %iowait %steal %idle
2.96 0.02 0.78 2.79 0.00 93.45

Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s avgrq-sz avgqu-sz await svctm %util
sda 1.74 46.44 11.39 20.45 420.41 536.11 30.04 0.56 17.32 6.60 21.01
sda1 0.00 0.00 0.00 0.00 0.00 0.00 10.38 0.00 22.09 21.85 0.00
sda2 0.00 0.00 0.00 0.00 0.00 0.00 49.15 0.00 14.23 13.81 0.00
sda3 1.74 46.44 11.39 20.45 420.40 536.11 30.04 0.56 17.32 6.60 21.01

----------------------------------------------------------------------
function iil_ParseResult($string, $from = '') {
   $a = explode(' ', trim($string));
   if (count($a) >= 2) {
      $res = strtoupper($a[1]);
      if ($res == 'OK') {         
         return 0;
      } else if ($res == 'NO') {
         write_log('errors', 'imap said No!');
         return -1;
      } else if ($res == 'BAD') {
         write_log('errors', 'imap said BAD!');
            log_system_stat();
         return -2;
      } else if ($res == 'BYE') {
         write_log('errors', 'imap said BYE!');
            log_system_stat();
         return -3;
      }
   }

   write_log('errors', $from);
   write_log('errors', 'unknow imap connect info!');
   write_log('errors', $a);
   write_log('errors', $_SERVER['HTTP_REFERER']);
   write_log('errors', $_SESSION['username']);
    log_system_stat();

   return -4;
}
------------------------------------------------------------------------
I have set $rcmail_config['imap_debug'] = true;

But it is hard to me to find some useful information.

yk