I was using php 5.3 to call a SOAP service that need some custom http header fields. However, when I used HttpRequest to add the headers and send request to the server, the response said the token is invalid. And I used wireshark to sniff the package and found that the token was truncated. It is very possible that the php_http extension has some limitations on the http header fields. Can anyone explain that to me? BTW, I was using php on a windows machine, and I just download the php_http.dll file and made it work. I didn't compile anything from the source code.