UK Broadband

Since upgrading to a wireless hub and option2 broadband the broadband disconnects every now and then when Im using Xnews to download from newsgroups.
Previously (with bt broadband dial up) I could down load from up to 3 newsgroups at the same time - now Im lucky if 1 works for more than a few minutes.
Xnews tries to re-connect but seems to stop eventually with a 480 authentication denied error.
Any ideas (Ive searched this forum and the BT one but cant see a similar problem)?

Its a possibility that there many be a problem with the hub itself, so either sending it back to BT if that's possible or ask them to replace it.