The URL for Paypal has changed. You may receive a warning message about an expired certificate when using the Paypal gateway code.
Depending on which Paypal interface you are using, edit paypalgateway.asp or a similar name (for VP-ASP 3.x name will be paypalshopcheckout.asp) and change
https://secure.paypal.com/cgi-bin/webscr
to
https://www.paypal.com/cgi-bin/webscr