The problem is still here for me. Other sites affected is:
1up.com
excaliberpc.com
The problem is that Cogent wont exchange internet traffic with Telia/Sonera (major internet exchanger/provider) in Europe. Article about it here:
http://gigaom.com/2008/03/14/the-telia-cogent-spat-could-ruin-web-for-many/