For 64 bit users, make sure you have the latest ActivClient version. In Firefox 4 this actually works fairly easily now.
Can I use my screen reader with the new Firefox?.Identify problems caused by third-party modules in Firefox for Windows.Troubleshoot Firefox issues caused by malware.Firefox crashes when I insert CAC card into smart card reader.dll to load to configure Firefox to use a CAC reader when using MS Smart Card Provider instead of ActiveClient cannot load file 'ACPKCS211.DLL' to security device module and I cannot view my certs from a cac card reader.