I just downloaded the Ubuntu 12.04 iso file in order to do a fresh install. However, I am not able to burn it to my DVD which only holds 4.7GB because it is too big (>6GB).
You must have been downloading from a different source, or something went terrible wrong during the download. Ubuntu 12.04 has a size of 695 MB. Small enough to fit on a CD. Ubuntu 12.10 however do require a DVD (~800 MB).
Please get the iso file from Ubuntu.com