I've been unable to access Maplin.co.uk and no images would load in their emails for about the past month. What was strange was that pings and tracert to the site was fine, and all other internet access and web sites where also ok. I contacted Maplin tech support, who has also had other people with similar problems, and suggested that it was a proxy problem with NTL. I found this thread discussing the issue and the page with the NTL proxy list at:
http://www.cableforum.co.uk/forum/article.php?a=10 and after I changed the proxy of both the browser & email client, the site now resolves and emails load the images. So my advice is to change your proxy and let NTL know that they've got an issue. Phil.