Could be filed under Reproducable Crash, bit it only happens when compiled with oracle support.

Config:
./configure --prefix=/data/apache/php --enable-sigchild --with-oci8=/ora01/app/oracle/product/8.1.6 --without-xml --without-mysql --with-apxs=/data/apache/bin/apxs 

Backtrace:
(gdb) r -X
Starting program: /data/apache/bin/httpd -X
Cannot access memory at address 0x2b3c1b14
(gdb) bt
#0  0x2aab5f21 in _dl_debug_state () at dl-debug.c:56
#1  0x2ac2d156 in _dl_close (map=0x80c47f0) at dl-close.c:195
#2  0x2ab4b430 in dlclose_doit (handle=0x80c47f0) at dlclose.c:26
#3  0x2aab5c3b in _dl_catch_error (errstring=0x2ab4d080,
    operate=0x2ab4b418 <dlclose_doit>, args=0x80c47f0) at dl-error.c:141
#4  0x2ab4b8b9 in _dlerror_run (operate=0x2ab4b418 <dlclose_doit>,
    args=0x80c47f0) at dlerror.c:125
#5  0x2ab4b3fe in dlclose (handle=0x80c47f0) at dlclose.c:32
#6  0x806f950 in ap_os_dso_unload ()
#7  0x804f270 in unload_module ()
#8  0x805101e in run_cleanups ()
#9  0x804f84d in ap_clear_pool ()
#10 0x805f923 in standalone_main ()
#11 0x80601c3 in main ()
#12 0x2ab669cb in __libc_start_main (main=0x805fe7c <main>, argc=2,
    argv=0x7ffff9c4, init=0x804e870 <_init>, fini=0x809419c <_fini>,
    rtld_fini=0x2aab5e60 <_dl_fini>, stack_end=0x7ffff9bc)
    at ../sysdeps/generic/libc-start.c:92