I'm having a similar problem where My daytime speed is around 7 Megs but drops down to around dial up speeds sometimes in the evening, I sent a complaint E-Mail to BT on Wednesday had a couple of calls about it on Friday, and an engineer appeared today who did shed loads of tests which proved the line was fine, installed a broadband kit for free (special master skt and cat five to the router) When he eventually left he said he would get them to monitor the exchange loading in the evenings for a week or two, so we will see. He was not impressed with his diagnostics that said the line length to the exchange was 4 kilometres, it's only about 500mtrs.
