squid exit on signal 6

Hi, I'm new to squid and have a strange problem.

My squid is runnnig on FreeBSD 2.2.5(R).
It often terminates by unknown signal and leave messages in
/var/log/messages
as follows:

Feb 27 18:36:02 Sara /kernel: pid 169 (squid), uid 65534: exited on signal
6
Feb 28 12:43:29 Sara /kernel: pid 169 (squid), uid 65534: exited on signal
6
Mar 1 12:25:02 Sara /kernel: pid 169 (squid), uid 65534: exited on signal
6
Mar 2 08:22:11 Sara /kernel: pid 169 (squid), uid 65534: exited on signal
6
Mar 2 10:41:06 Sara /kernel: pid 169 (squid), uid 65534: exited on signal
6
Mar 6 18:41:57 Sara /kernel: pid 169 (squid), uid 65534: exited on signal
6

The squid is 1.1.20.

Is there any who have been suffered from such case
and Does anyone know how should I cope with this problem.

TIA,

Hiroshi Takagi
Received on Sun Mar 08 1998 - 22:57:43 MST