HTTP dialog with the history server - what am I doing wrong here?

12:16:01 connect from 127.0.0.1 localhost 8080 40444
12:16:01 connecting to proxy.research.ge.com:8080
12:16:01 GET http://tclers.tk/conferences/tcl/2008-10-01.tcl HTTP/1.1
12:16:01 Accept: */*
12:16:01 Host: tclers.tk
12:16:01 User-Agent: Mozilla/5.0 (Unix; U; Linux 2.4.21-15.0.4.EL; en) Tkchat/1.448 Tcl/8.6a3
12:16:01 Connection: close
12:16:01 Accept-Charset: utf-8
12:16:01 Cache-Control: no-cache
12:16:01 Pragma: no-cache
12:16:01 
12:16:01 
12:16:02 HTTP/1.1 404 Not Found
12:16:02 Date: Wed, 01 Oct 2008 16:16:50 GMT
12:16:02 Server: Tcl-Webserver/3.5.1 May 27, 2004
12:16:02 Content-Type: text/html
12:16:02 Content-Length: 182
12:16:02 Connection: close
12:16:02 
12:16:02 
12:16:02     <title>Httpd_Error: 404</title>
12:16:02     Got the error <b>Not Found</b><br>
12:16:02     while trying to obtain <b>/conferences/tcl/2008-10-01.tcl</b>.
12:16:02 <br>/conferences/tcl/2008-10-01.tcl