Don't know about Easynet (sorry, Sky) but I used to have an account with
http://news.individual.net/ until not too long ago. Yes its a paid service, but its only €10 per year and its infinately faster and more reliable than ntl's nntp server. This gives full access to all groups, expect (quote) "The newsserver does not offer binary groups and some alt.* sub-hierarchies".
HTH