That's odd, as far as I know /sockwrite -n has always worked this way: it will only append a CRLF if the line doesn't already end with one. At least that's what the 6.35 help file says.

You can also send the two CRLFs at the end like so:

Code:
  sockwrite -n $sockname GET /get.html HTTP/1.1
  sockwrite $sockname host: www.mirc.com $str($crlf,2)


This works as you would expect.