Problems connecting through Comcast's network to a Japanese site.

Hello, My users are complaining that they have been unable to get to a number of Japanese sites directly through the Comcast network. The sites are up and if connection attempts are made through one of your competitors, the connections go through. It looks like the packets are going into the Comcast network but not getting out the other side; however, I'm only running traceroutes from inside my internal network, so I could be mistaken. The specific site that they are attempting to connect to is "pso2.jp". They were down last week due to a large DDOS attack; however, they are back up now. Is this the appropriate place to place a request to have the issue looked into, or is there a better way? (I couldn't see a way to open a ticket online) Thanks for any assistance you can offer., Senjak