Did you install the 5.5 update? I see no other recourse but to scrap Nero otherwise. Software clashes happen. I use Easy Cd Creator 6 with no problems. I do not have much patience for troublesome software. Someone may see your post and supply an easy fix for you. Here is the update and more.
http://www.nero.com/us/631941507584102.html
http://www.nero.com/us/631933457317970.html