I notice some problem on Tue & Wed night. When I was browsing it was taking ages to load new sites. Then all of a sudden it would become fast again. I tried using Opera and Internet Explorer. And process activity was only at about 5%.
Normally I would have suspect my connection had dropped, but my MSN Messanger and IRC were still working.
So it could be realted to DNS resolution.
I also got a BT Error page at one point.. not sure what that was related to.