I do not have any problems burning ISO's in Vista, but needed an app to do it. Unless you know the steps to burn an ISO in Vista and can detail them here. When I tried, it apparently only copies the ISO as a single file, which will not run as a normal CD/DVD because the file structure and files will nor be there, just the single ISO file. Of course, I could have done something wrong.
The ISO Recorder linked earlier works just fine and is quick, small and works as a popup menu item.