VW -check that your ISP has been updated with the new IP address for PPRuNe -although the DNS is still the same the IP address has changed after the move to the new server and it seems that some ISPs have yet to catch up. I had the same problem for over 2 weeks with Cable & Wireless Lite and also Onetel - both of which I use depending one time of day/ week / cost. In the end I got fed up as despite e-mails and promises to 'look into it' neither ISP has sorted it out - so I signed up another account with Freeserve which for now I just use for 'Ppruning'. This goes against the grain as I despise Dixons and everything they stand for (their business practices suck) - so much for my principles.
Anyway - try another ISP and see how you get on.