Firefox Error sec_error_reused_issuer_and_serial

In Firefox 3.0.1, to create a certificate exception that will allow access to printers on your local network with web interfaces...

• Go to...
  Tools >> Options >> Advanced >> Encryption >> [View Certificates]
  
• If there is a certificate for your printer, delete it.
  (NOTE: "Certificate Name" may be the IP address)
  
• Click [Add Exception].
  
• For "Location", enter the printer's network name or IP address.
  
• Click [Get Certificate].
  
• Response will say the site is trying to use invalid information. Ignore it.
  
• Make sure the checkbox in the lower left, "Permanently store this exception", is checked.
  
• Click on [Confirm Security Exception].