Is it only blitzcoder giving you dns errors? I remember in the office a while back I had to switch which DNS servers the connection used as BT was having issues with their servers and we couldn't access our company e-mail or anything.
Out of the regular sites I visit it's BlitzCoder and CodersWorkShop (both 81.21.69.111) that I've had trouble with. I'm using BT and have sent them an email. Eikon, yep that's the one I've been trying. I was hoping I had it wrong. What I don't understand is not being able to contact the site via the IP address. Doesn't the DNS server simply act as a YellowPages?
Just in case anybody is as stupid as me... I had firewall blocked 'an address' which happened to be the blitzcoder server. Thanks again for the suggestions.