Burns DVDs but not CDs (Lite-On DVD RECORDER DVD -R RW)

[qanda]This thread is about the Lite-On DVD RECORDER DVD±R RW. Click here to see full specs[/qanda]Hi, I’m running Nero 7 on Windows XP Home Ed. and it was working perfectly until just now. I can burn DVDs without any problems but it won’t burn any CDs. After adding the files to the list it says the disc is empty but the disc is already in the drive.
I’ve reinstalled the software and tried different brands of software and new/different CDs with no gain. Any ideas would be greatly appreciated!