ok. Lets try turn off the certificate verification to see if you get through ( we will turn it back on)....
On the Security tab in the Internet Properties dialog box, select the Local intranet zone, and then click Sites.
In the Local intranet dialog box, click Advanced.
Click to clear the Require server verification (https
for all sites in this zone check box.
Also in the Security tab in the Internet Properties dialog box, select the Trusted sites zone, and then click Sites.
In the Trusted sites dialog box, click to clear the Require server verification (https
for all sites in this zone check box.
Close IE7 and try the sites again.
I'm also wondering if you could try "https://www.paypal.com" (without "s) directly instead of the
www.paypal.com and whether you have tried running IE7 as an Administrator?
Steve