An internal intranet site with a self generated certificate was displaying correctly using IE but not using Firefox. Firefox displayed an error with the string.
SEC_ERROR_BAD_SIGNATURE
Both browsers were correctly referencing the private CA to check the certificate.
Regenerating the certificate and avoiding older lower encryption types resolved the problem.
Search :
SHA-1 SEC_ERROR_BAD_SIGNATURE
Below are similar scenarios which were resolved by
regenerating the certificate.