happy new year to all readers of this post!
Are you trying the fglrxinfo in a terminal window from your desktop environment (GUI)? If you are, can you post the output of xrandr (you can try
xrandr > ~/whatever
and it will create a file in your home directory called whatever in which you will find what you need to post). The info from xrandr might tell us if you have upgraded the drivers (you will have more screen resolutions available).
Secondly, if you are trying the command fglrxinfo in a desktop environment, try logging out and running from tty1 (black screen; press ctrl+alt+F1), and then tell me what the output of the command is.
Finally, it is also my recommendation to "sudo" for acting as root. You can try an alias in your .bashrc file located in your directory so you don't have to type sudo all the time, but no other way around it. Acting as root can be dangerous to the system (until you get the hang of it, and even then you'll realize why the fuss about this).
P.S. Could you also post what model of ATI card you have?