Since you have a total of 4 ide channels you should be able to use the other two for your cd rom.... Try to leave your A04 on a channel all by itself....
Most motherboards with 4 IDE channels will use the last 2 for RAID but will allow them to be used as a normal channel instead of RAID...
Set your hard drives as master/slave on the same ide...
Then set your DVD-R/CD Rom as Master & Master on two seperate ide channels....