You should not use your A04 for CD-R copies.... It will not make a exact copy because the A04 cannot read sub-channel data...
Whenever possible use a 100 % compatible Clone CD burner and Clone CD 4 software for your CD-R backups....
Also CD-RW & DVD-RW are not rec. for use on a V4...(weak lasers)
You may find that your laser is starting to get weak... Also ALWAYS burn at a low speed ( I always burn CD-R's @ 4X) Takes a little longer but you get a MUCH better copy.....
Also you didn't mention what type of media you are using....
It is NOT AS important on CD-R's BUT on DVD-R's ALWAYS USE HIGH Quality media.... Since the grooves on a DVD-R are much closer together it is harder to read than a cd-r.... The cheaper quality DVD-R's have a poor reflectivity rate thus making them harder to read.....