Could you try with an older gettext version?
Like 0.10.40, which I know works for sure.

I've tried gettext 0.10.40 but got the same unreferenced symbol.

Try this configure line:

./configure --disable-all --with-gettext=/path/to/gettext/install/prefix

And if that causes the same problem, try this:

./configure --disable-all --with-gettext

This way we can rule out the possibility of other extensions
being the reason..

I've tried compiling it with 
./configure --disable-all --with-gettext=/path/to/gettext/install/prefix
but still failed. I've given up for now as I've other issues which are more important...

Works fine here, user has more important issues to deal with and can't provide feedback, and this most likely is some user error anyway.

Hello

I have similar problem here with php 4.3.3, gettext 0.13 and SUNWspro 5.5 compiler. I tried to run configure like you said ("./configure --disable-all --with-gettext=/opt/local/gettext/") and here's a result for latest command :

cc  -Imain/ -I/export/home/compile/soft/web/php-4.3.3/main/ -DPHP_ATOM_INC -I/export/home/compile/soft/web/php-4.3.3/include -I/export/home/compile/soft/web/php-4.3.3/main -I/export/home/compile/soft/web/php-4.3.3 -I/export/home/compile/soft/web/php-4.3.3/Zend -I/opt/local/gettext//include  -D_POSIX_PTHREAD_SEMANTICS -I/export/home/compile/soft/web/php-4.3.3/TSRM  -Xa -fast -native -xstrconst -mt -xarch=v9  -c main/internal_functions.c -o main/internal_functions.o  && echo > main/internal_functions.lo
/bin/sh /export/home/compile/soft/web/php-4.3.3/libtool --silent --preserve-dup-deps --mode=link cc -export-dynamic -Xa -fast -native -xstrconst -mt -xarch=v9  -L/usr/ucblib -L/opt/local/gettext//lib -xarch=v9 -R /usr/ucblib -R /opt/local/gettext//lib ext/gettext/gettext.lo ext/standard/array.lo ext/standard/base64.lo ext/standard/basic_functions.lo ext/standard/browscap.lo ext/standard/crc32.lo ext/standard/crypt.lo ext/standard/cyr_convert.lo ext/standard/datetime.lo ext/standard/dir.lo ext/standard/dl.lo ext/standard/dns.lo ext/standard/exec.lo ext/standard/file.lo ext/standard/filestat.lo ext/standard/flock_compat.lo ext/standard/formatted_print.lo ext/standard/fsock.lo ext/standard/head.lo ext/standard/html.lo ext/standard/image.lo ext/standard/info.lo ext/standard/iptc.lo ext/standard/lcg.lo ext/standard/link.lo ext/standard/mail.lo ext/standard/math.lo ext/standard/md5.lo ext/standard/metaphone.lo ext/standard/microtime.lo ext/standard/pack.lo ext/standard/pageinfo.lo ext/standard/parsedate.lo ext/standard/quot_print.lo ext/standard/rand.lo ext/standard/reg.lo ext/standard/soundex.lo ext/standard/string.lo ext/standard/scanf.lo ext/standard/syslog.lo ext/standard/type.lo ext/standard/uniqid.lo ext/standard/url.lo ext/standard/url_scanner.lo ext/standard/var.lo ext/standard/versioning.lo ext/standard/assert.lo ext/standard/strnatcmp.lo ext/standard/levenshtein.lo ext/standard/incomplete_class.lo ext/standard/url_scanner_ex.lo ext/standard/ftp_fopen_wrapper.lo ext/standard/http_fopen_wrapper.lo ext/standard/php_fopen_wrapper.lo ext/standard/credits.lo ext/standard/css.lo ext/standard/var_unserializer.lo ext/standard/ftok.lo ext/standard/aggregation.lo ext/standard/sha1.lo regex/regcomp.lo regex/regexec.lo regex/regerror.lo regex/regfree.lo TSRM/TSRM.lo TSRM/tsrm_strtok_r.lo TSRM/tsrm_virtual_cwd.lo main/main.lo main/snprintf.lo main/spprintf.lo main/php_sprintf.lo main/safe_mode.lo main/fopen_wrappers.lo main/alloca.lo main/php_scandir.lo main/php_ini.lo main/SAPI.lo main/rfc1867.lo main/php_content_types.lo main/strlcpy.lo main/strlcat.lo main/mergesort.lo main/reentrancy.lo main/php_variables.lo main/php_ticks.lo main/streams.lo main/network.lo main/php_open_temporary_file.lo main/php_logos.lo main/output.lo main/memory_streams.lo main/user_streams.lo Zend/zend_language_parser.lo Zend/zend_language_scanner.lo Zend/zend_ini_parser.lo Zend/zend_ini_scanner.lo Zend/zend_alloc.lo Zend/zend_compile.lo Zend/zend_constants.lo Zend/zend_dynamic_array.lo Zend/zend_execute_API.lo Zend/zend_highlight.lo Zend/zend_llist.lo Zend/zend_opcode.lo Zend/zend_operators.lo Zend/zend_ptr_stack.lo Zend/zend_stack.lo Zend/zend_variables.lo Zend/zend.lo Zend/zend_API.lo Zend/zend_extensions.lo Zend/zend_hash.lo Zend/zend_list.lo Zend/zend_indent.lo Zend/zend_builtin_functions.lo Zend/zend_sprintf.lo Zend/zend_ini.lo Zend/zend_qsort.lo Zend/zend_multibyte.lo Zend/zend_execute.lo sapi/cgi/cgi_main.lo sapi/cgi/getopt.lo main/internal_functions.lo -lintl -lresolv -lm -ldl -lnsl -lsocket  -o sapi/cgi/php
Undefined                       first referenced
 symbol                             in file
php_gettext_module_entry            main/internal_functions.o
ld: fatal: Symbol referencing errors. No output written to sapi/cgi/php
*** Error code 1
make: Fatal error: Command failed for target `sapi/cgi/php'


Any ideas ?

With best regards
Martynas