Hi, I recently had similar problems to you and the way I got round this was to use external name servers (to my adsl router). If you want to use name servers based in the uk, add these lines to your /etc/resolv.conf:
Code:
nameserver 62.41.128.51
nameserver 62.41.128.52
I'm sorry I don't have a better answer, I would love one myself! You can use them until some one can figure out the problem I suppose. Maybe try asking your ISP for their nameservers IP's if you want some closer to home.