i have an acer aspire computer that up until a few months never had any problems reading or copying to blank discs. now it doesn't read or even acknowledge that a blank disc has been inserted. i've tried everything from cd-r, cd+r, cd-rw, cd+rw, dvd-r, dvd+r, dvd+rw, dvd-rw and it no longer reads any of them. it reads music cds fine, so any ideas why this is happening?