The HTTP headers don't look right to me actually.. Shouldn't it be as follows:

POST /dwws-app/DWWSApp?cmd=UploadSubmPage.uploadSubm
HOST: www.environet.gov.on.ca
Content-Length: 3059
* * * THE REST * * *
[download]

I know that some servers may also require HTTP version included with the POST header, like so:

POST /dwws-app/DWWSApp?cmd=UploadSubmPage.uploadSubm HTTP/1.1
* * * * * *
[download]

Update: you can get more info on HTTP protocol at the w3.org site. On my home PC (Win2000) I have a great HTTP dump tool which allows you to have a closer look at HTTP traffic. You could get a free Win32 TCPDUMP utility here. This is the one I use.

_____________________

# Under Construction
[download]