When you install LWP, you should find GET, POST, and HEAD in your perl/bin directory. Might be batch files if on Win32. GET has an option to view the response chain of headers. So on the command line, you could type

   GET -s -e http://target.site.com/path/to/file.gz

and you should be able to see what comes back. Also, as that's obviously a dummy string, have you checked the spelling to make sure you're not requesting an invalid path or file?

Cheers