Ok
download this
Select the 2nd option from the first section and download and install the file
Once installed, run the program
it should give you an option window, select burn ISO image, click next
make sure the window is maximized so you see all the options
click the button to the far right of the box called 'Image file', navigate to the ISO file you downloaded for Ubuntu, click open
select the drive you are burning to in the next box down
click burn iso
when finished - exit deep burner
open the disc in My Computer and see if it's any different and try to boot from it
I've not been able to test this one fully, just did a quick download as I'm on a different PC and this download is slightly different to the one i'm used to - but it looks fairly straightforward
once you get it booting up, i won't be much help i'm afraid, not to much experience with Linux except a couple of installs