Give this a look:

http://www.google.com/linux?hl=en&q=copy+iso+to+dvd&btnG=Search

K3b or Gnomebaker will do it. I'm kind of partial to K3b.

In Ubuntu you can just right click on the iso file and one of
the options is to burn it to CD using the included Brasero
utility. No "extra" software required.

try K3b its what I use to burn movies on

in ubuntu i just right click image and choose write to disk

Yes, K3b is the best, I think. Only the Burn button does not burn ISO's. You
have to go in the menu and there's an ISO burn option. It is real easy to
do.