I've got php-4.0.6 compiled with apache 1.3.20 (config options below), running horde 1.3.4, IMP 2.3.7, Turba 0.0.2. I'm doing a full upgrade from an older version of all of these. 

The old setup works fine for user "Amy", and everyone else, this new install seems to work for every account that I've tried *except* Amy's. When I login, apache segfaults (11). Normally I would think that this might be because of mysql or imap (running pine4.33's newest IMAP), but it works fine for all the other users. 

I can reproduce the error every time I login as Amy, but not when I login as myself. 

Here is my configure for php:
./configure \
--with-zlib --with-mm --with-mysql=/usr \
--with-mcal=../libmcal-0.6.orig \
--with-config-file-path=/usr/local/lib \
--with-imap=/usr/local/src/pine4.33/imap \
--with-gettext --enable-ftp --with-gdbm \
--with-apache=../apache_1.3.20 --with-mcrypt 
--disable-magic-quotes

Here is my configure for apache:
./configure --enable-module=mime_magic  
--enable-module=unique_id 
--enable-module=rewrite --enable-module=setenvif 
--enable-module=speling --enable-module=expires 
--enable-module=info --enable-module=log_agent 
--enable-module=log_referer --enable-module=so 
--enable-suexec 
--suexec-caller=www-data --suexec-docroot=/usr/var/www 
--activate module=src/modules/php4/libphp4.a

Horde/IMP folks say that it is a php problem.

gdb backtrace:

gdb ./httpd -f conf/httpd.conf
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This GDB was configured as "i686-pc-linux-gnu"...

/usr/local/apache/bin/conf/httpd.conf: No such file or directory.
(gdb) run -X
Starting program: /usr/local/apache/bin/./httpd -X

Program received signal SIGSEGV, Segmentation fault.
0x2775e0 in realloc () from /lib/libc.so.6
(gdb) bt
#0  0x2775e0 in realloc () from /lib/libc.so.6
#1  0x81d8f36 in fs_resize (block=0x85674b8, size=2048) at fs_unix.c:46
#2  0x81e8e61 in imap_sort (stream=0x84b8fb0, charset=0x0, spg=0x852cd70,
    pgm=0x8515a60, flags=1) at imap4r1.c:1667
#3  0x81d0003 in mail_sort (stream=0x84b8fb0, charset=0x0, spg=0x852cd70,
    pgm=0x8515a60, flags=1) at mail.c:3501
#4  0x80b1e9f in php_if_imap_sort (ht=5, return_value=0x852cd54, this_ptr=0x0,
    return_value_used=1) at php_imap.c:2773
#5  0x817e25a in execute (op_array=0x83a14ac) at ./zend_execute.c:1504
#6  0x8144874 in zend_execute_scripts (type=8, file_count=3) at zend.c:752
#7  0x809757f in php_execute_script (primary_file=0xbffff318) at main.c:1206
#8  0x81555fc in apache_php_module_main (r=0x8346af4, display_source_mode=0)
    at sapi_apache.c:89
#9  0x80941f2 in send_php ()
#10 0x809422a in send_parsed_php ()
#11 0x8188c99 in ap_invoke_handler ()
#12 0x819d5ff in process_request_internal ()
#13 0x819d666 in ap_process_request ()
#14 0x8194586 in child_main ()
#15 0x8194741 in make_child ()
#16 0x81948bc in startup_children ()
#17 0x8194f2c in standalone_main ()
#18 0x819575c in main ()
#19 0x2232db in __libc_start_main () from /lib/libc.so.6
(gdb)