I bought a lite-on cdrw/dvd rom about 1.5yrs back... now using nero 6, and the windows xp inbuilt cd writing tool, it cannot burn cds... I cleaned the lens etc, no use... I usually burn quite a few cds every now and then... What is the usual lifetime/ max no. of cds a writer can burn? Also, which do u think is the best/fastest brand out there?