dnssubmit queue overload error message

my squid running on openBSD 4.1

i have dns_childern 32

but i m facing a problem of queue overloading

cache.log shows this error message...

dnsSubmit: queue overload, rejecting xxxxxxxxxx
dnsSubmit: queue overload, rejecting xxxxxxxxxx
dnsSubmit: queue overload, rejecting xxxxxxxxxx
dnsSubmit: queue overload, rejecting xxxxxxxxxx

plz help me to solve this....