[AWS] "Post Timeout" result from AWS.Client.Post?

[Jacob Sparre Andersen]

I am working on a small tool, which sends two HTTP 
POST messages to a web server; the first to log in, and the 
second to fetch some data which only are available once I am 
logged in:

begin
    Create (Connection => Merril_Lynch,
            Host       => "www.mlx.ml.com");

    Post (Connection => Merril_Lynch,
          Result     => Login_Page,
          Data       => "URL=/&hdnLoginFlag=1&TARGET=/_mem_bin/protected/" &
                        "entload.asp&REALMOID=&SMAUTHREASON=0&USER=" &
                        User_Name & "&PASSWORD=" & Password,
          URI        => "/siteminderagent/forms/login.fcc");

    Ada.Text_IO.Put_Line ("Login page:");
    Ada.Text_IO.Put_Line ("»" & Message_Body (Login_Page) & "«");

    Post (Connection => Merril_Lynch,
          Result     => ERCT,
          Data       => "datevalue=" & MLX_Date & "&hdnAsofdate=" & MLX_Date &
                        "&hidCuspID=&ColState=&hdnSrcApp=&hdnPortID=" &
                        "&hdnMthEndDate=&hdnViewState=&txtIndex=ERCT" &
                        "&txtFromDate=" & MLX_Date & "&SelOldNew=1" &
                        "&cboConfiguration=6840&cboFilter=0&iPage=&IndexVal=" &
                        "&Param1=&strWhere=&Param2=&SortVariable=" &
                        "&SortVariable1=&SortVariable2=&SortVariable3=" &
                        "&SortBy1=&SortBy2=&SortBy3=&SortString=&SortType=" &
                        "&Download=&OrderBy=&ConfigId=6840&CriteriaID=" &
                        "&NoOfConfig=&Source=1&ProfileName=",
          URI        => "/MLIndex/Bin/downloadindex.asp");

    Ada.Text_IO.Put_Line ("ERCT data:");
    Ada.Text_IO.Put_Line ("»" & Message_Body (ERCT) & "«");
end;

In both cases the message body is reported as "Post Timeout" 
(almost instantaneously).

Why does this happen?

I have a similar tool written as a shell script using 
"wget", which works fine, so the post data should be 
correct.

Greetings,

Jacob
-- 
"Don't get me wrong, perl is an OK operating system, but it
  lacks a lightweight scripting language."