If it is a server setting in the php.ini file then it is most likely this
Code:
; cgi.rfc2616_headers configuration option tells PHP what type of headers to
; use when sending HTTP response code. If it's set 0 PHP sends Status: header that
; is supported by Apache. When this option is set to 1 PHP will send
; RFC2616 compliant header.
; Default is zero.
;cgi.rfc2616_headers = 0
You should determine if your host allows a local php.ini file to adjust settings and if so have them provide you with what is currently loaded with php from there one can adjust settings