Hallo. I found myself in the same situation on Fedora 8.
I know it's been 7 months since you posted this but here is the solution :
Check out the info on :
The error i encountered was :
ERROR: Can't connect to an X server. Please try the following:
- generate or merge `.Xauthority'. You can merge with:
$ xauth merge <path-to-user-with-X-rights>/.Xauthority
In terminal type :
the return value can be used as a parameter in the next step.
I created my /root/.Xauthority file by executing in terminal :
mkxauth -c xxx
where xxx should be replaced by the return value of the command hostname