Go back to an earlier version of nero 5.5 (184.108.40.206 or 220.127.116.11) or retuen to Nero 5.048.Each of these versions is more stable then the last 2 versions.
If you would like to keep 18.104.22.168, uninstall the software, including InCD, if it is installed. Edit the registry of all Nero and Ahead entries (I can tell you how if you need to know). Do a search of your hard drive and remove all ahead and nero files. Reboot your computer. Before installing Nero again, turn off all unnecessary programs. You do this by pressing CTRL-ALT-DEL and highlighting and deleting all programs except systray and explorer. Without rebooting, install nero and InCD, if you want it, too. Reboot. This will give you a fresh install without former program remnants interfering.
Please post again if you have any questions. (Note this install method was given to me by an employee of Ahead).