Pleased to say I solved my slow download problem.

I thought back to what I was doing when the problem started to happen. I've seen it mentioned in another thread and I don't know how significant it is, but the night my problems started I had had to re-install I-Tunes.

So I used the Nortons firewall to block I-Tunes from accessing the net and then re-installed LW and now it's back to downloading at the speeds I was running at last week.

Maybe a coincidence, but worth sharing I thought.