ok, on this linux box I'm running from my php 4-3-4 src dir (has to be
that version):

[root_at_new php-4.3.4]# ./configure --with-mysql
--with-apxs=/www/bin/apxs --with-curl=/usr/local/curl

I downloaded a binary distribution of curl with SSL from here:

http://www.bell-labs.com/cgi-user/wwexptools/gensnapshot?curl

Now, when I run the php configure script, I get the following:

checking for CURL support... yes
checking for cURL 7.9.8 or greater... libcurl 7.11.2
checking for curl_easy_perform in -lcurl... no
configure: error: There is something wrong. Please check config.log
for more information.

[root_at_new php-4.3.4]# tail -10 config.log
#line 20481 "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 curl_easy_perform();

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

---
And that's it! Not quite sure what's going on. I don't have full
knowledge of this linux server, but I do think it's a Mandrake distro:
[root_at_new php-4.3.4]# cat /etc/redhat-release
Mandrake Linux release 9.2 (FiveStar) for i586
Note that I can't even build cURL 7.12.1 on this server, as I get the following:
[root_at_new curl-7.12.1]# ./configure --with-ssl
...
checking whether we are using the GNU C++ compiler... no
checking whether g++ accepts -g... no
checking dependency style of g++... none
checking how to run the C++ preprocessor... /lib/cpp
configure: error: C++ preprocessor "/lib/cpp" fails sanity check
See `config.log' for more details.
[root_at_new curl-7.12.1]# tail -10 config.log
#define PACKAGE_TARNAME "curl"
#define PACKAGE_VERSION "-"
#define STDC_HEADERS 1
#define VERSION "7.12.1"
#define _FILE_OFFSET_BITS 64
#endif
#ifdef __cplusplus
void exit (int);
configure: exit 1
--
Any help greatly appreciated - please CC me on replies as I'm on the digest. 
Thanks!
Scott