Because of the specific way that this manifests, I'm forced to wonder if specific shared libraries have a part to play in this. As such, I'm including the output of ‘ldd’ as appropriate below (I've not been able to see an obvious culprit, but somebody else may):

ldd /opt/jports/libexec/apache22-worker/modules/libphp5.so 
        libhistory.so.5 =>       /opt/jports/lib/libhistory.so.5
        libreadline.so.5 =>      /opt/jports/lib/libreadline.so.5
        libtermcap.so.1 =>       /usr/ucblib/libtermcap.so.1
        libmysqlclient.so.15 =>  /opt/jports/lib/mysql/libmysqlclient.so.15
        libldap-2.3.so.0 =>      /opt/jports/lib/libldap-2.3.so.0
        liblber-2.3.so.0 =>      /opt/jports/lib/liblber-2.3.so.0
        libgmp.so.3 =>   /opt/jports/lib/libgmp.so.3
        libintl.so.3 =>  /opt/jports/lib/libintl.so.3
        libt1.so.5 =>    /opt/jports/lib/libt1.so.5
        libfreetype.so.6 =>      /opt/jports/lib/libfreetype.so.6
        libpng12.so.0 =>         /opt/jports/lib/libpng12.so.0
        libz.so =>       /opt/jports/lib/libz.so
        libssl.so.0.9.8 =>       /opt/jports/lib/libssl.so.0.9.8
        libcrypto.so.0.9.8 =>    /opt/jports/lib/libcrypto.so.0.9.8
        libdb-4.4.so =>  /opt/jports/lib/libdb-4.4.so
        libpcre.so.0 =>  /opt/jports/lib/libpcre.so.0
        libresolv.so.2 =>        /lib/libresolv.so.2
        libm.so.1 =>     /lib/libm.so.1
        libsocket.so.1 =>        /lib/libsocket.so.1
        libnsl.so.1 =>   /lib/libnsl.so.1
        libcurl.so.3 =>  /opt/jports/lib/libcurl.so.3
        libfbopenssl.so =>       /opt/jports/lib/libfbopenssl.so
        libgssapi.so.4 =>        /opt/jports/lib/libgssapi.so.4
        libkrb5.so.17 =>         /opt/jports/lib/libkrb5.so.17
        libasn1.so.6 =>  /opt/jports/lib/libasn1.so.6
        libcom_err.so.1 =>       /opt/jports/lib/libcom_err.so.1
        libroken.so.16 =>        /opt/jports/lib/libroken.so.16
        libidn.so.11 =>  /opt/jports/lib/libidn.so.11
        libxml2.so.2 =>  /opt/jports/lib/libxml2.so.2
        libiconv.so.2 =>         /opt/jports/lib/libiconv.so.2
        libc.so.1 =>     /lib/libc.so.1
        libgcc_s.so.1 =>         /opt/jports/lib/libgcc_s.so.1
        librt.so.1 =>    /lib/librt.so.1
        libcrypt_i.so.1 =>       /lib/libcrypt_i.so.1
        libgen.so.1 =>   /lib/libgen.so.1
        libsasl2.so.2 =>         /opt/jports/lib/libsasl2.so.2
        libdl.so.1 =>    /lib/libdl.so.1
        libmp.so.2 =>    /lib/libmp.so.2
        libdoor.so.1 =>  /lib/libdoor.so.1
        libpthread.so.1 =>       /lib/libpthread.so.1
        libaio.so.1 =>   /lib/libaio.so.1
        libmd5.so.1 =>   /lib/libmd5.so.1
        /usr/platform/SUNW,UltraAX-i2/lib/libc_psr.so.1
        libthread.so.1 =>        /lib/libthread.so.1
        /usr/platform/SUNW,UltraAX-i2/lib/libmd5_psr.so.1

ldd /opt/jports/bin/mysql
        libcurses.so.1 =>        /lib/libcurses.so.1
        libmysqlclient.so.15 =>  /opt/jports/lib/mysql/libmysqlclient.so.15
        librt.so.1 =>    /lib/librt.so.1
        libcrypt_i.so.1 =>       /lib/libcrypt_i.so.1
        libgen.so.1 =>   /lib/libgen.so.1
        libsocket.so.1 =>        /lib/libsocket.so.1
        libnsl.so.1 =>   /lib/libnsl.so.1
        libssl.so.0.9.8 =>       /opt/jports/lib/libssl.so.0.9.8
        libcrypto.so.0.9.8 =>    /opt/jports/lib/libcrypto.so.0.9.8
        libz.so =>       /opt/jports/lib/libz.so
        libstdc++.so.6 =>        /opt/jports/lib/libstdc++.so.6
        libm.so.1 =>     /lib/libm.so.1
        libgcc_s.so.1 =>         /opt/jports/lib/libgcc_s.so.1
        libc.so.1 =>     /lib/libc.so.1
        libaio.so.1 =>   /lib/libaio.so.1
        libmd5.so.1 =>   /lib/libmd5.so.1
        libdl.so.1 =>    /lib/libdl.so.1
        libmp.so.2 =>    /lib/libmp.so.2
        /usr/platform/SUNW,UltraAX-i2/lib/libc_psr.so.1
        /usr/platform/SUNW,UltraAX-i2/lib/libmd5_psr.so.1

ldd /opt/jports/libexec/apache22-worker/bin/httpd 
        libm.so.1 =>     /lib/libm.so.1
        libpcre.so.0 =>  /opt/jports/lib/libpcre.so.0
        libaprutil-1.so.0 =>     /opt/jports/lib/apache22-worker/libaprutil-1.so.0
        libexpat.so.1 =>         /opt/jports/lib/libexpat.so.1
        libiconv.so.2 =>         /opt/jports/lib/libiconv.so.2
        libapr-1.so.0 =>         /opt/jports/lib/apache22-worker/libapr-1.so.0
        libuuid.so.1 =>  /lib/libuuid.so.1
        libsendfile.so.1 =>      /lib/libsendfile.so.1
        librt.so.1 =>    /lib/librt.so.1
        libsocket.so.1 =>        /lib/libsocket.so.1
        libnsl.so.1 =>   /lib/libnsl.so.1
        libpthread.so.1 =>       /lib/libpthread.so.1
        libc.so.1 =>     /lib/libc.so.1
        libgcc_s.so.1 =>         /opt/jports/lib/libgcc_s.so.1
        libdl.so.1 =>    /lib/libdl.so.1
        libaio.so.1 =>   /lib/libaio.so.1
        libmd5.so.1 =>   /lib/libmd5.so.1
        libmp.so.2 =>    /lib/libmp.so.2
        libthread.so.1 =>        /lib/libthread.so.1
        /usr/platform/SUNW,UltraAX-i2/lib/libc_psr.so.1
        /usr/platform/SUNW,UltraAX-i2/lib/libmd5_psr.so.1