Postgresql extension

Hi, Sorry if this question has already been addressed here, but I was unable to find it. I am running nanoweb 2.1.1 + php431 (installed as package) on Windows XP.. I am trying to access a postgres db using php. I have followed the instructions to add the postgres extension to php by placing php_pgsql.dll in c:\php\extensions dir and uncommenting the appropriate extension line in php.ini. But when I start nanoweb I get the following error "The procedure entry point php_sprintf could not be located in the dynamic link library php4ts.dll" Can anyone tell me if there is a solution to this problem. Thanks