security certificate message window appearing

  march 15:48 11 Jul 2005
Locked

never had this happen before & dont quite know what to do to put it right

when trying to log onto o2 phone site I get a message saying

Information you exchange with this site cannot be viewed by others.

However there is a problem with the sites security certificate

Under which it states

v the security certificate is from a trusted certifying authority

? the security certificate has expired or is not yet valid

v the security certificate matches the name of the page you are trying to view

do you want to proceed?

Yes no view certificate

on choosing 'view certificate' it says the certificate is not yet valid or has expired

if I choose 'yes' it just takes me to the site I want to be on as it always use to

can anyone tell me

how do I stop this window appearing

& will the site still be secure if the certificate is not valid

march

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