Freebsd amd64 PHP 5.2.5 Internal Server Error

Hello, I have a freebsd 6.2 server running amd64 version with php 5.2.5. The web server is Apache 1.3.39. The following bit of code works on the 32 bit version running on the same Freebsd, Apache 1.3.39 build but causes a 500 internal server error when run on the amd64 bit version. The amd64 bit version has the web application mounted as a nfs mount. $file_name = MOUNT_DIR . "/test.txt";

                   if (!$write_handle = fopen($file_name, 'w')) {
                       return false;
                   }
                                     //set conforming strings to true
                   $ins_fields_sql = "SET standard_conforming_strings to TRUE;";
                   fwrite($write_handle, $text_to_write . "\n");
                   #### THIS WRITE HAPPENS TO THE FILE

                   foreach ($ar_orders as $key => $value) {
                    ### INTERNAL SERVER ERROR
                   }

Has anyone come across this? -- Regards, Anjan Upadhya