Hmm.. ok. First of all, you can have both Nero and Roxio installed on the same system. They don't seem to like each other and may cause each other not to work correctly. I'd recommend removing Roxio as quite a few people here seem to have problems with it. Then see if the drive recognises blank media.
If it still doesn't work, try rebooting in safe mode (in case some sort of software drivers are causing those conflicts) and see if the drive works.
If that still doesn't work, test the writer in another system. This is to confirm if it is a software or hardware problem. If the drive doesn't work, you know for sure it is defective. However, if it does work, then it is some sort of drive on your system causing the conflict, something booting into safe mode won't bypass. These usually fall into the dark realms of copy protection drivers installed with games.