3) Switched to Chrome, unable to access the secure login page of my electricity supplier and with the same error, encrypted page includes non-encrypted content: https://www.britishgas.co.uk/Login/L...toploginbutton With dummy login info the page instead of reporting a login error redisplayed itself identically. The next dummy login resulted in what I assume was the correct red text and login error. The same https error occurs whether Tor is running or a direct connection or following restarting the tor service, both from the guest and host (firefox). Note though the same page opens securely on my Android. (HTML of the page giving the error attached.)

4) The Chrome delicious plugin works intermittently, with various bugs randomly exhibited (the popup redisplaying itself cleared on submit; the popup form incorrectly laid out and/or of varying height; predictive tag completion text not displaying [edit 6/5/11: displaying predictive text tags twice in the select list).

Netstat on both host and guest do not show anything that I would consider unusual (I am not a network admin. though). If anyone can point me in the direction as to what to look at next?

[Quick update to the above, about an hour or so later the network lost its sluggishness, the British Gas secured login page became fully accessible without any errors, and the Delicious plugin is working flawlessly (as it should!).]