Invalid Certificate for Router GUI page

I'm trying to connect to the router/firewall (Netgear FVS318) on my home network. It worked for a while, but now I get the following message; Secure Connection Failed An error occurred during a connection to 192.168.1.1. You have received an invalid certificate. Please contact the server administrator or email correspondent and give them the following information: Your certificate contains the same serial number as another certificate issued by the certificate authority. Please get a new certificate containing a unique serial number. (Error code: sec_error_reused_issuer_and_serial) I can connect with IE, it post a warning first, but I can ignore and proceed to the GUI page. I prefer to use FF. I'm running the NoScript add on. How can I update or change permissions for an internal site/device.