Problem with websites

I been having constant problems going into sites like Paypal, online banking, etc. This message will pop up: "The certificate for this website was signed by an unknown certifying authority. You might be connecting to a website that is pretending to be “www.paypal.com” which could put your confidential information at risk. Would you like to connect to the website anyway?" Even I try to continue it will show a blank page. I try using IE but the same happens. I am using Airport Express, could it cause this problem? Any help would be grateful. Thanx.

paypal is apparently having some problems at this time....they were upgrading something...and it seems they also upgraded into a large problem..or so I read.