Yes that would seem to be the case as far as I have found.
Only secure sites like Banks or building societies. THere is no error message. I can access the site and look at my accounts but I cannot alter anything like transfer money or arrange direct debits.
And it appears to be just specific to my computer since I have no problem accessing the same sites via a friends machine who uses a different ISP.
I can still buy items from shopping sites and the like.