Unable to start debugging on the web server



I am working on an ASP.Net project which for some historico-technical
reasons isn't run locally but directly on the web server.

It works ok, but whereas I was at some point after struggling for
months able to debug on the web server, I can't anymore.

Here's the message :

"Error while trying to run project: Unable to start debugging on the
web server. You do not have privileges to debug the web server process.
Contact an Administrator to get the debug privileges on the server. You
may also want to refer to the ASP.NET and ATL Server debugging topic in
the online documentation."

The remote debugger has been installed on the remote machine, my login
is both in Administrators and in debugger Users and still I get kicked
back with bloody error messages. I have been searching the net over and
over and although I found different references to my error messages,
none of the solutions provided seem to work for me. Can any generous
developer deliver me from these persistent troubles that imped me from
sleeping :)

..Net Developer