If you mean that your drive wont burn LightScribe:
You must install Lightscribe drivers (www.lightscribe.com). But I had a similar problem with my BenQ 1655 (I had those drivers installed). I installed Nero 6 and everything worked OK. Apparently there's a bug in Nero 7.
If you mean that your drive wont burn CD's or DVD's:
Check your DMA settings, defrag your HDD, update Nero, try using other burning programs (Nero CD/DVD speed, ImgBurn, etc)...