Safari can’t establish a secure connection to the server www.google.com

Question

If I try to navigate to any of the following pages:

• http://google.com/reader
• https://encrypted.google.com/

I get an error message in Safari saying:

Safari can't open the page "https://encrypted.google.com/" because Safari can’t establish a secure connection to the server "encrypted.google.com"

I also find that on the Gmail page many images are missing and when I try to go the image location I see the same error as above. Here's a pic of the missing images:

In chrome I have the same issue but with a different error as follows:

Error 107 (net::ERR_SSL_PROTOCOL_ERROR): SSL protocol error.

I am not using a proxy and this behaviour has started recently for seemingly no apparent reason although I did get a new router about 2 weeks ago. Why am I experiencing these problems?