Was running PHP 4.1.2 no probs...
D/L PHP 4.2.2, unpack, then configure with same configure command that I used on my 4.1.2 source:

./configure \
   --with-apxs=/usr/local/apache/bin/apxs \
   --with-mysql=/usr/local/mysql \
   --with-zlib \
   --with-zlib-dir==../zlib-1.1.4 \
   --with-gd=../gd-1.8.4 \
   --with-jpeg-dir=../jpeg-6b \
   --with-png-dir=../libpng-1.2.1 \
   --enable-sigchild \
   --enable-track-vars


I get this error after 200 or so lines of output:

Configuring extensions
checking if the location of ZLIB install directory is defined... yes
checking for ZLIB support... yes
checking for gzgets in -lz... no
configure: error: ZLIB extension requires zlib >= 1.0.9


Here's the last bit of config.log:

configure:9674: checking if the location of ZLIB install directory is defined
configure:9723: checking for ZLIB support
configure:10037: checking for gzgets in -lz
configure:10056: gcc -o conftest -g -O2  -DLINUX=22 -DMOD_SSL=208105 -DUSE_HSREG
EX -DEAPI -DUSE_EXPAT  conftest.c -lz  -lcrypt -lresolv -lm -ldl -lnsl  -lresolv
 -lcrypt 1>&5
/tmp/ccxKPnPF.o: In function `main':
/usr/src/php-4.2.2/configure:10052: undefined reference to `gzgets'
collect2: ld returned 1 exit status
configure: failed program was:
#line 10045 "configure"
#include "confdefs.h"
/* Override any gcc2 internal prototype to avoid an error.  */
/* We use char because int might match the return type of a gcc2
    builtin and then its argument prototype would still apply.  */
char gzgets();

int main() {
gzgets()
; return 0; }