With newer versions of MySQL (>=3.22.32), Apache segfaults on startup.  I'm using the i386 RPMs available for download from the mysql site, with no modifications; Apache has undergone a number of site modifications, including SSL and frontpage support, but reversing these patches has no impact on the crash.

gdb backtrace (generated using 'gdb /usr/sbin/httpd core'  on the output of 'httpd -X'):

#0  0x4049a404 in _init () from /lib/libpthread.so.0
(gdb) bt
#0  0x4049a404 in _init () from /lib/libpthread.so.0
#1  0x805a32c in make_sock ()
#2  0x805a691 in setup_listeners ()
#3  0x805b3c7 in standalone_main ()
#4  0x805ba7f in main ()
#5  0x400b71eb in __libc_start_main (main=0x805b7f8 <main>, argc=2,
    argv=0xbffff914, init=0x804efd0 <_init>, fini=0x8079a0c <_fini>,
    rtld_fini=0x4000a610 <_dl_fini>, stack_end=0xbffff90c)
    at ../sysdeps/generic/libc-start.c:90
(gdb) 


Configure options to php:
CFLAGS="-fPIC" ./configure --prefix=/usr --with-apxs=/usr/sbin/apxs \
        --with-config-file-path=/etc/httpd --enable-safe-mode \
        --with-exec-dir=/usr/bin --with-system-regex  --disable-debug \
        --with-zlib --with-gd --with-mysql --enable-sysvshm \
        --enable-sysvsem --with-freetype --with-snmp \
        --enable-magic-quotes

If '--with-mysql' is removed from the list of options, the segfaults disappear.  If other options are removed (notably --with-freetype and --with-snmp), no change is noted.

Previously, I had successfully compiled php on this machine using mysql 3.21; no abberant behavior was noted at the time.