the sites it works fine on....are they all UK sites? maybe they are on a bit of infrastructure that avoids a certain piece of kit that doesnt deal with non-broadcom generated packets well during peak times.

Sounds far-fetched i know, just trying to figure out something that fits the facts

In reply to a post by drsox:

3) MTUs changed and tested.. that was one of my first thoughts as AOL used to have similar symptoms when on the 'old dsl network' and the 'incorrect' setting of 1500. In this TT case; lowering the MTU seems to make the problem worse.

What MTU did you try?
TT has a LLU presence at our exchange and I am finding I need to set my TT customers LLU to 1400 before secure (https) sites work.

I know I certainly tried 1400. (As that was the trick for the old AOL network ).

Tom - www.mouselike.org