On my Ubuntu 6.10 system the easy way to create an ISO image file is as follows:
  1. Insert the CD (or DVD) into the drive. A CD icon should appear on the desktop after it auto mounts
  2. Right click on the desktop icon and from the pop up menu select "Copy Disc..."
  3. On the small dialogue that appears the "Copy disc to:" field probably displays the CD/DVD writer drive. Change it to "File Image".
    1. To make a direct CD/DVD media copy on a blank disk leave the field set to the writer drive.
  4. Select the "Write" button
  5. On the next screen modify the file name (keep the ISO file suffix) and directory name as required.
  6. Select "OK"
The copy starts.