Firefox "OCSP" Error Warning

Online Certificate Security Protocol (OCSP) is a newer way for Web browsers to confirm the validity of an SSL certificate. At this time, the online registration system doesn't employ the use of OCSP. If you have Firefox set for OCSP, you will see this error when trying to login to the registration system:

From the main menu, use this path: Tools > Options (WinXP, Linux) or Firefox > Preferences (Mac OS X)

Under the main tab "Advanced" and the sub-tab "Security", click the "Verification" button. Make sure that "Do not use OCSP for certificate validation" is selected.