Are you use the Creative Labs Serial Number? If you're not, it will not work correctly. The following is listed at the Nero home site:
Users of the Creative BlasterÂ® CD-RW 4224 may get asked to input a serial-number for using Nero. In this case, please use the following Serial-number to unlock Nero:
This version of Nero and the serial number are working with Creative CD-Recorders only
Hope this helps...