Squid sometimes doesn't use unlinkd

I've asked this before but got no replies, but I can't imagine I'm the
only one seeing this. Every once in a while our squid server (1.1.20 novm)
decides not to use unlinkd and does the unlinking itself. Here's part
from an strace on a running squid:

lseek(76, 0, SEEK_SET) = 0
read(76, "HTTP/1.0 200 OK\r\nDate: Tue, 24"..., 8192) = 1352
lseek(76, 0, SEEK_CUR) = 1352
select(13, [11 12], [], NULL, {0, 0}) = 0 (Timeout)
select(13, [11 12], [], NULL, {0, 0}) = 0 (Timeout)
connect(77, {sin_family=AF_INET, sin_port=htons(8080), sin_addr=inet_addr("194.159.73.7")}, 16) = 0
select(13, [11 12], [], NULL, {0, 0}) = 0 (Timeout)
unlink("/var/spool/squid/0B/65/0007D65B") = 0
unlink("/var/spool/squid/02/EE/000A6EE2") = 0
unlink("/var/spool/squid/0F/C0/000D0C0F") = 0
unlink("/var/spool/squid/07/C2/0001BC27") = 0
unlink("/var/spool/squid/02/EA/00032EA2") = 0
unlink("/var/spool/squid/01/4A/000704A1" <unfinished ...>

It shouldn't be doing this - it should write() a request to the unlinkd
pipe .. Unlinkd is running but idle.

Anyone have a clue?

Mike.

-- 
 Miquel van Smoorenburg |  The dyslexic, agnostic, insomniac lay in his bed
    miquels@cistron.nl  |  awake all night wondering if there is a doG