problem in starting apache in win2k with mcrypt and mhash module

Hello i've uncommended the mcrypt and mhash line in c:\winnt\php.ini. then i try to start the apache but encounter the following error msg "The procedure entry point _ecalloc could not be located in the dynamic link library php4ts.dll" "Unable to load dynamic library 'c:\php\extensions\php_mcrypt.dll" - The specified procedure could not be found." "mhash: Unable to initialize module Module compiled with module API=20010901, debug=0, thread-safety=1 PHP compiled with module API=20020429, debug=0, thread-safety=1 There options need to match" i m sure that the "php_mcrypt.dll" is already in that location. i've also tried to change the "extension_dir" in c:\winnt\php.ini to c:\php c:\php\extensions\ c:\winnt c:\winnt\system32 and copied all the required dll to corresponding directories. same error was encountered when i start the apache. can you advice how can i solve it? i would like to use the mhash and mcrypt functions. Terence