Install Problem Apache 2, PHP 5.0.0B4, MySQL 4.0.17 on Win XP-P - Missing PHP_MYSQL.DLL

I have installed the above into respective directories and set up the config files according to install directions. The test phpinfo page/script works fine. But when I try to get MySQL linked to PHP properly by uncommenting extension=php_mysql.dll and pointing the 'extension_dir' = c:\php\ext I get the following error on Apache startup "Unable to load dynamic library 'php_mysql.dll' - The specified procedure could not be found." I have tried moving all ext DLL's to c:\windows\system32 & re-pointing extension_dir, but still the same problem error message. Any suggestions for what I am missing or any solution and/or workarounds for this greatly appreciated ?? - Art