What he meant is check your burst rate by using CD-DVD Speed in Nero. Remember to put a data DVD into your drive, click Run Test and select Burst Rate. If it turns out to be something less than 23 MB/s (IE: 17MB/s for PIO) then:
Log in with your administrator account, go to device manager and double click on the bus your DVD burner is in (usually the secondary IDE channel) and select DMA if available.
Win9X: Go to device manager but click on the drive itself not the bus. Check DMA tag then reboot.
If it stays in PIO mode then you have IDE driver/hardware problems, which has nothing to do with the drive.