Crash is 100% repeatable - script previously worked until I grabbed a latest horde CVS update - tried recompiling binary etc, no dice

Other php scripts work correctly - not sure which command in the PHP script is triggering the SIGSEGV

Setup:
apache_1.3.27 
php-4.3.0
horde (CVS latest 12/30/2002)
imp (CVS latest 12/30/2002)

attempting horde/login.php

***apache error_log***
Cannot allocate memory
unknown error
Cannot allocate memory
unknown error
unknown error
[Mon Dec 30 09:29:26 2002] [notice] child pid 24928 exit signal Segmentation fault (11)
***

***gdb backtrace***:
GNU gdb Red Hat Linux (5.2-2)
Copyright 2002 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 "i386-redhat-linux"...
(gdb) run -X
Starting program: /usr/local/apache/bin/httpd -X

Program received signal SIGSEGV, Segmentation fault.
0x42082587 in memset () from /lib/i686/libc.so.6
(gdb) bt
#0  0x42082587 in memset () from /lib/i686/libc.so.6
#1  0xffffffff in ?? ()
#2  0x4002a275 in mxfree (ptr=0x0, size=4294967295) at xmemory.c:118
#3  0x40029eea in internal_end_mcrypt (td=0x8326cf8) at mcrypt.c:104
#4  0x40029e95 in internal_init_mcrypt (td=0x8326cf8, key=0x82db554, lenofkey=32, IV=0x831939c) at mcrypt.c:93
#5  0x40029f42 in mcrypt_generic_init (td=0x8326cf8, key=0x82db554, lenofkey=32, IV=0x831939c) at mcrypt.c:118
#6  0x40130c66 in zif_mcrypt_generic_init (ht=3, return_value=0x8349b2c, this_ptr=0x0, return_value_used=0)
    at /usr/local/src/web/php-4.3.0/ext/mcrypt/mcrypt.c:502
#7  0x401fe320 in execute (op_array=0x82da624) at /usr/local/src/web/php-4.3.0/Zend/zend_execute.c:1596
#8  0x401fe4de in execute (op_array=0x832ed7c) at /usr/local/src/web/php-4.3.0/Zend/zend_execute.c:1640
#9  0x401fe4de in execute (op_array=0x834c6cc) at /usr/local/src/web/php-4.3.0/Zend/zend_execute.c:1640
#10 0x401fe4de in execute (op_array=0x834a8cc) at /usr/local/src/web/php-4.3.0/Zend/zend_execute.c:1640
#11 0x401fe4de in execute (op_array=0x825de8c) at /usr/local/src/web/php-4.3.0/Zend/zend_execute.c:1640
#12 0x401ebf30 in zend_execute_scripts (type=8, retval=0x0, file_count=3) at /usr/local/src/web/php-4.3.0/Zend/zend.c:864
#13 0x401c59c1 in php_execute_script (primary_file=0xbffff4c0) at /usr/local/src/web/php-4.3.0/main/main.c:1573
#14 0x402058c2 in apache_php_module_main (r=0x8246f8c, display_source_mode=0) at /usr/local/src/web/php-4.3.0/sapi/apache/sapi_apache.c:55
#15 0x402063c6 in send_php (r=0x8246f8c, display_source_mode=0, filename=0x0) at /usr/local/src/web/php-4.3.0/sapi/apache/mod_php4.c:556
#16 0x4020641a in send_parsed_php (r=0x8246f8c) at /usr/local/src/web/php-4.3.0/sapi/apache/mod_php4.c:571
#17 0x0809a38f in ap_invoke_handler ()
#18 0x080af813 in process_request_internal ()
#19 0x080af874 in ap_process_request ()
#20 0x080a65e5 in child_main ()
#21 0x080a67b4 in make_child ()
#22 0x080a6928 in startup_children ()
#23 0x080a6fa0 in standalone_main ()
#24 0x080a781f in main ()
#25 0x42017589 in __libc_start_main () from /lib/i686/libc.so.6
***

***php config.status***:
# ./configure  --with-apxs --with-openssl --with-zlib --with-bz2 --enable-ftp --with-mcrypt --with-mhash --with-mm --with-pgsql=/usr/local/pgsql --with-mcal=../
libmcal --with-system-regex --without-mysql --with-gettext --with-ldap --with-imap --with-kerberos --with-ssl --with-imap-ssl --with-dom --with-dom-xslt --with-
dom-exslt --enable-mime-magic --enable-debug
***