everything just stopped working yesterday. we already tried 
reinstalling it in our server then started the service in 
diagnostic mode. after the "ready for requests" message we 
tried to open the dev center, admin console, etc but we 
keep on receiving an error "internet explorer cannot open 
the internet site http://localhost:81/?command=devcenter. 
the server returned an invalid or unrecognized response." 
we still have 11 days remaining to work on our evaluation 
copy.

You might want to confirm which ports Screensurfer is 
running on--start it in diagnostic mode, and it will display 
the port it is listening on for the terminal emulation (web 
gateway) port.  Probably 80 or 82.

Then, try hand-keying the URL in a browser to point to the 
local machine (do it on the server SS is installed on), as 
in:

http://127.0.0.1:80  (if port 80).

If that works, you may have something up with the HOSTS file 
in \winnt\system32\drivers\etc that has altered or lost the 
localhost definition.

Another thing to check is if you are using a proxy server 
which your IE is routed through, the proxy server's 
configuration may have recently been altered such that 
localhost is now in limbo.  If so, you need to update your 
IE configuration for connections so that localhost isn't 
routed through the proxy server.

If it was the key, SS would say so at startup.