Squid die with Segment Violation.

Sorry if this is a FAQ, but I've read the FAQ and the mailing list
archives and could not locate any response for this question.

My squid-2.2.STABLE4 (with several patches), running on a Sun
UltraSparc, Solaris 2.6, 512 MB of memory, dies, several times a day,
leaving the following message in cache.log:

FATAL: Received Segment Violation...dying.

I have compiled squid with the following options in configure:

./configure --enable-icmp --enable-cache-digests
--enable-err-language=Spanish --enable-async-io=64 --enable-snmp
--enable-poll --enable-ipf-transparent
--disable-ident-lookups --enable-kill-parent-hack

Previously squid was compiled with the option --enable-dl-malloc with
the same result.

The core trace output is:

GNU gdb 4.18
Copyright 1998 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you
are
welcome to change it and/or distribute copies of it under certain
conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB. Type "show warranty" for
details.
This GDB was configured as "sparc-sun-solaris2.6"...
Core was generated by `squid -NsY'.
Program terminated with signal 9, Killed.
Reading symbols from /usr/lib//libpthread.so.1...done.
Reading symbols from /usr/lib//libm.so.1...done.
Reading symbols from /usr/lib//libresolv.so.2...done.
Reading symbols from /usr/lib//libsocket.so.1...done.
Reading symbols from /usr/lib//libnsl.so.1...done.
Reading symbols from /usr/lib//libc.so.1...done.
Reading symbols from /usr/lib/libdl.so.1...done.
Reading symbols from /usr/lib/libmp.so.2...done.
Reading symbols from
/usr/platform/SUNW,Ultra-1/lib/libc_psr.so.1...done.
Reading symbols from /usr/lib/libthread.so.1...done.
Reading symbols from /usr/lib/nss_dns.so.1...done.
Reading symbols from /usr/lib/nss_files.so.1...done.
#0 0x6fdd3470 in __sigprocmask () from /usr/lib/libthread.so.1
(gdb) where
#0 0x6fdd3470 in __sigprocmask () from /usr/lib/libthread.so.1
#1 0x6fdcb02c in _resetsig () from /usr/lib/libthread.so.1
#2 0x6fdca8f0 in _sigon () from /usr/lib12 0x3b0fc in ftpListingStart (ftpState=0x3da2c40) at ftp.c:403
#13 0x3c84c in ftpDataRead (fd=44, data=0x3da2c40) at ftp.c:887
#14 0x33bf4 in comm_poll (msec=64) at comm_select.c:362
#15 0x50408 in main (argc=0, argv=0xeffffd44) at main.c:627
(gdb)

Thanks in advance,

-- 
Jose Manuel Sanchez Bretones     C.I.C.A.
e-mail: breton@cica.es           Avda.Reina Mercedes, s/n
                                 41012.- Sevilla (España)
                                 Tlf: 95-4623811