The NERO Linux 4 manual isn't very clear about exactly how NERO detects devices.
Check to make sure that you see the expected device names for your recorder.
Make sure that the "sys" and "proc" file-systems are mounted.
Download and read the Nero Linux 4 user guide. It has a section on the device name requirements and driver requirements for NERO.
Reinstall NERO Linux 4. It's possible that NERO requires a specific version of some library. Reinstalling NERO may install the correct version of the libraries.
After that, I recommend contacting NERO support.