PHP3 installed fine, PHP4 complains

I'm trying to install PHP 4.0.6 on a fresh install of Apache 1.3.20. The make complained after the seemless configure was run. The error I get is ; gcc -I. -I/usr/src/php-4.0.6/ext/standard -I/usr/src/php-4.0.6/main -I/usr/ src/php-4.0.6 -I/usr/src/apache_1.3.20/src/include -I/usr/src/apache_1.3.20/ src/os/unix -I/usr/src/php-4.0.6/Zend -I/usr/src/php-4.0.6/ext/xml/expat/xml tok -I/usr/src/php-4.0.6/ext/xml/expat/xmlparse -I/usr/src/php-4.0.6/TSRM - DSUPPORT_UTF8 -DXML_BYTE_ORDER=12 -g -O2 -c filestat.c && touch filestat.lo filestat.c: In function `php_if_diskfreespace': filestat.c:157: storage size of `buf' isn't known make[3]: *** [filestat.lo] Error 1 make[3]: Leaving directory `/usr/src/php-4.0.6/ext/standard' make[2]: *** [all-recursive] Error 1 make[2]: Leaving directory `/usr/src/php-4.0.6/ext/standard' make[1]: *** [all-recursive] Error 1 make[1]: Leaving directory `/usr/src/php-4.0.6/ext' make: *** [all-recursive] Error 1 I installed a newer GNU fileutils, but that didn't help, so I reluctantly decided to install php-3.0.18 which went fine. I really want to get php4 installed though. Can anyone tell me what the hang-up is? I assume it's the outdated install, missing some lib(s) somewhere... I can't re-install the machine as it does a few vital processes which can't be interrupted for long.