tail -f error_log|grep Segf
[Sun Mar 15 16:45:59 2009] [notice] child pid 23546 exit signal Segmentation fault (11), possible coredump in /web/core
[Sun Mar 15 16:45:59 2009] [notice] child pid 23547 exit signal Segmentation fault (11), possible coredump in /web/core
[Sun Mar 15 16:46:00 2009] [notice] child pid 23580 exit signal Segmentation fault (11), possible coredump in /web/core
[Sun Mar 15 16:46:00 2009] [notice] child pid 23581 exit signal Segmentation fault (11), possible coredump in /web/core
[Sun Mar 15 16:46:00 2009] [notice] child pid 23582 exit signal Segmentation fault (11), possible coredump in /web/core
[Sun Mar 15 16:46:00 2009] [notice] child pid 23583 exit signal Segmentation fault (11), possible coredump in /web/core
[Sun Mar 15 16:46:01 2009] [notice] child pid 23605 exit signal Segmentation fault (11), possible coredump in /web/core
[Sun Mar 15 16:46:01 2009] [notice] child pid 23606 exit signal Segmentation fault (11), possible coredump in /web/core
[Sun Mar 15 16:46:01 2009] [notice] child pid 23607 exit signal Segmentation fault (11), possible coredump in /web/core
[Sun Mar 15 16:46:01 2009] [notice] child pid 23608 exit signal Segmentation fault (11), possible coredump in /web/core
[Sun Mar 15 16:46:01 2009] [notice] child pid 23609 exit signal Segmentation fault (11), possible coredump in /web/core

# gdb -c core /usr/local/apachesmse/bin/httpd
GNU gdb 6.4.90-debian
Copyright (C) 2006 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 "x86_64-linux-gnu"...Using host libthread_db library "/lib/libthread_db.so.1".

Reading symbols from /usr/lib/libssl.so.0.9.8...done.
Loaded symbols for /usr/lib/libssl.so.0.9.8
Reading symbols from /usr/lib/libcrypto.so.0.9.8...done.
Loaded symbols for /usr/lib/libcrypto.so.0.9.8
Reading symbols from /lib/libm.so.6...done.
Loaded symbols for /lib/libm.so.6
Reading symbols from /usr/local/apache/lib/libaprutil-1.so.0...done.
Loaded symbols for /usr/local/apache/lib/libaprutil-1.so.0
Reading symbols from /usr/local/apache/lib/libexpat.so.0...done.
Loaded symbols for /usr/local/apache/lib/libexpat.so.0
Reading symbols from /usr/local/apache/lib/libapr-1.so.0...done.
Loaded symbols for /usr/local/apache/lib/libapr-1.so.0
Reading symbols from /lib/librt.so.1...done.
Loaded symbols for /lib/librt.so.1
Reading symbols from /lib/libcrypt.so.1...done.
Loaded symbols for /lib/libcrypt.so.1
Reading symbols from /lib/libpthread.so.0...done.
Loaded symbols for /lib/libpthread.so.0
Reading symbols from /lib/libdl.so.2...done.
Loaded symbols for /lib/libdl.so.2
Reading symbols from /lib/libc.so.6...done.
Loaded symbols for /lib/libc.so.6
Reading symbols from /usr/lib/libz.so.1...done.
Loaded symbols for /usr/lib/libz.so.1
Reading symbols from /lib/ld-linux-x86-64.so.2...done.
Loaded symbols for /lib64/ld-linux-x86-64.so.2
Reading symbols from /lib/libnss_compat.so.2...done.
Loaded symbols for /lib/libnss_compat.so.2
Reading symbols from /lib/libnsl.so.1...done.
Loaded symbols for /lib/libnsl.so.1
Reading symbols from /lib/libnss_nis.so.2...done.
Loaded symbols for /lib/libnss_nis.so.2
Reading symbols from /lib/libnss_files.so.2...done.
Loaded symbols for /lib/libnss_files.so.2
Reading symbols from /lib/libnss_dns.so.2...done.
Loaded symbols for /lib/libnss_dns.so.2
Reading symbols from /lib/libresolv.so.2...done.
Loaded symbols for /lib/libresolv.so.2
Reading symbols from /usr/local/apache/modules/mod_fastcgi.so...done.
Loaded symbols for /usr/local/apache/modules/mod_fastcgi.so
Failed to read a valid object file image from memory.
Core was generated by `/usr/local/apache/bin/httpd -k start'.
Program terminated with signal 11, Segmentation fault.
#0  apr_pollset_add (pollset=0x0, descriptor=0x7fffced412a0) at poll/unix/epoll.c:150
150         if (pollset->flags & APR_POLLSET_NOCOPY) {

(gdb) bt
#0  apr_pollset_add (pollset=0x0, descriptor=0x7fffced412a0) at poll/unix/epoll.c:150
#1  0x000000000047aead in child_main (child_num_arg=<value optimized out>) at prefork.c:532
#2  0x000000000047b2c4 in make_child (s=0xff96f0, slot=109) at prefork.c:746
#3  0x000000000047bb66 in ap_mpm_run (_pconf=<value optimized out>, plog=<value optimized out>, s=<value optimized out>)
    at prefork.c:881
#4  0x000000000042a2a7 in main (argc=3, argv=0x7fffced416b8) at main.c:740


as you can see the only external module is mod_fastcgi, latest snapshot, http://www.fastcgi.com/dist/mod_fastcgi-SNAP-0811090952.tar.gz, using an external fastcgi script via tcp/ip.