$mailObject = imap_header($mbox, $i);
kills it for me.

Configure command: './configure' '--with-oci8' '--with-imap' '--with-mysql' '--enable-track-vars' '--with-gd' '--with-freetype' '--with-ttf' '--with-xml' '--enable-inline-optimization' '--with-apache=/root/source/apache/' '--enable-sysvshm'


Starting program: /www/bin/httpd -X
(no debugging symbols found)...
Program received signal SIGABRT, Aborted.
0x40480111 in __kill ()
(gdb) bt
#0  0x40480111 in __kill ()
#1  0x4047fd66 in raise (sig=6) at ../sysdeps/posix/raise.c:27
#2  0x40481447 in abort () at ../sysdeps/generic/abort.c:88
#3  0x81a52eb in fatal ()
#4  0x819591f in mail_fetch_structure ()
#5  0x80b6759 in php_if_imap_headerinfo ()
#6  0x812bded in execute ()
#7  0x8088d7c in php_execute_script ()
#8  0x80ac1c9 in apache_php_module_main ()
#9  0x80843fb in send_php ()
#10 0x808443c in send_parsed_php ()
#11 0x8152333 in ap_invoke_handler ()
#12 0x8165869 in ap_some_auth_required ()
#13 0x81658cc in ap_process_request ()
#14 0x815d16e in ap_child_terminate ()
#15 0x815d2fc in ap_child_terminate ()
#16 0x815d459 in ap_child_terminate ()
#17 0x815da86 in ap_child_terminate ()
#18 0x815e213 in main ()
#19 0x40479cb3 in __libc_start_main (main=0x815decc <main>, argc=2, argv=0xbffffcc4, 
    init=0x806aabc <_init>, fini=0x81d3f8c <_fini>, rtld_fini=0x4000a350 <_dl_fini>, 
    stack_end=0xbffffcbc) at ../sysdeps/generic/libc-start.c:78