dovecot kqueue problem

Hello.

dovecot-1.0.3 compiled with kqueue support periodically stop to accept
connections:

Listen queue not empty:

Current listen queue sizes (qlen/incqlen/maxqlen)
Proto Listen         Local Address
tcp4  6/0/8          *.143

however kevent return 0 pending event:

truss -D -p 71851
0.000000000 SIGNAL 17 (SIGSTOP)
0.000016761 gettimeofday({1188823517.452247},0x525bd0) = 0 (0x0)
0.000015923 gettimeofday({1188823517.452459},0x0) = 0 (0x0)
0.624191428 kevent(8,0x0,0,{},78,{0.623541000})  = 0 (0x0)
0.000016202 gettimeofday({1188823518.077250},0x525bd0) = 0 (0x0)
0.000015644 gettimeofday({1188823518.077458},0x0) = 0 (0x0)
1.000150078 kevent(8,0x0,0,{},78,{0.999542000})  = 0 (0x0)

$ uname -a
FreeBSD mailsupport.rambler.ru 7.0-CURRENT FreeBSD 7.0-CURRENT #6: Mon Aug 13 17:10:28 MSD 2007     citrin_at_mailsupport.rambler.ru:/usr/obj/usr/src/sys/MAIL  amd64

How I can debug this problem? It may dovecot bug as well as kernel bug.

How I can see list of knotes corresponding to given kqueue?

I try to see kqueue->kq_knlist (via kgdb), but it always empty, even
when dovecot work properly.

-- 
 WBR,
 Anton Yuzhaninov.