Problem solved.
For those with the same or a similar problem. Here's the simple solution.
Step 1: Add your username to the "dialout" group. In terminal type,
sudo adduser <username> dialout
Step 2: Create a udev (eg: 61-stellpad.rules) file in the directory: /etc/udev/rules.d/ with the contents as,
SUBSYSTEM=="usb", ATTRS{idVendor}=="1cbe", ATTRS{idProduct}=="00fd", MODE="0666"
Step 3: Save, unplug and replug the Stellaris board. All done.
[Note]: The solution was provided by a fellow Stellaris Launchpad user - Bernard.
Works perfectly now.
Cheers.