GnomeUI-WARNING * * While connecting to session manager: Authentication rejected .....

[John Mellor <John Kungfu-tse net>]

This error message continues - ... ,reason: None of the authentication
protocols specified are supported and host-based authentication failed.
Can anyone please tell me what it means?  I only seem to get it when
logged in as user john, but not when logged in as root. A similar
message is - ORBit-WARNING * * Request ping, ID -1073743920 was rejected
by the authentication mechanism! - . These messages pop up in my
xsession errors file every time I do anything like load a program,
connect to the internet etc.