If you have just moved to ADSL from dialup or ISDN, that would mean that you have moved from using a dynamic IP to using a new static IP in a new IP range - which to me would imply that the problem is simply that this new IP block is not yet widely recognised, i.e. hasn't yet made it into the server I-lines.
If the problem was with your computer I think you would be getting different error messages - like "unable to connect", or being disconnected for having no identd. etc.
"Connection refused" means, iirc, that you have successfully contacted the server, but that it isn't interested in you.