Firefox on Linux/UNIX and mutual authentication

[Frank Balluffi]

My investigation shows that Firefox on Windows (which uses Microsoft SSPI) 
sends RFC 2478 SPNEGO tokens with the mutual-required flag on and Firefox 
on Linux/UNIX (which uses GSSAPI) sends RFC 1964 Kerberos tokens with the 
mutual-required flag off.

Can anyone think of a reason why Firefox on Linux/UNIX should not set the 
mutual-required flag on? Thanks.

Frank