Nero

I have been using Nero for disk quality tester for some time, Lately the screen displays are differernt. Instead of a two tier display, only the top shows, and instead of a vertical display it only shows a thin horizontal line. Every one came out 100%, so I ran some older disks I knew to be faulty and the also came out with a 100% quality. Am I doing something wrong or has Nero changed the display?