I have recently noticed whilst surfing the internet on my Macbook Pro that it doesnt allow me visit certain websites such as Facebook, BBC etc. A message pops up reading:

'Safari can't verify the identity of the website "www.facebook.com".

The certificate for this website is invalid. You might be connecting to a website that is pretending to be "www.facebook.com", which could put your confidential information at risk. Would you like to connect to the website anyway?

Show Certificate, Cancel, Continue.'

Could anyone advise me onhow to fix this problem? Also when I shut the lid of the laptop and then reopen it or shut down and then turn on again it tells me I have to type in the wireless password in when in the past the computer has remembered it.

Are these problems linked at all?

Any help and guidance would be much appreciated.