Have put me out of admin

Root is the first user created in almost every distribution. So please do not try to create a root user.

To run applications as root including shell(which means basically means becoming root) in Ubuntu all one needs is to run sudo. Sudo is very useful.

sudo application_name options 

This is the way to use sudo. to solve the ICE issue. You need to change the ownership of the file to the user running the shell. Type this command.

 sudo chown marek:marek /home/marek/.ICEauthority

I assume marek is the username as it is in the directory /home/marek. Login as the first user created while setting up Ubuntu and then run the sudo chown command as above.

Corrections: the marek does not need to be the first user. Though the password would be the password of the one is in. Corrections: Added changes for users who are not in sudoers list.