Hello Tony,
it is a faulty base.i encountered a similar problem with my BT Studio 3500 product then I phoned 0800 1456789.
Or Visit the link below;
http://www.shop.bt.com/Article.aspx?ArticleId=2929
God bless you,brother.
Ask me any computer problems for free on;
http://www.allexperts.com/ep/3282-69854/Windows-XP/Lenny.htm
Lenny, May 2008