long ssh delay, no X forwarding in fresh FC3 install

[Alan Mead]

I just installed FC3 for the first time.  When I ssh onto that box
(from am FC1 box), there is a longish pause and then I see:

Warning: No xauth data; using fake authentication data for X11
forwarding.

I've googled this but found no understandable answer.   Apparently,
this involves xauth but I cannot grok it's man page. 

I'd like to prevent the delay and if there is a security problem, I'd
like to close it.  I'd also like to use X11 forwarding.  

Previously, IIRC, I didn't have to do anything special to enable X11
forwarding.  But now when I try to run an X program during the ssh
session, I get:

[amead at alan ~]$ xcalc
Xlib: connection to "localhost:10.0" refused by server
Xlib: Invalid MIT-MAGIC-COOKIE-1 key
Error: Can't open display: localhost:10.0

Any advice would be appreciated.  I don't know much about X.

-Alan