|Check in the BIOS screens to verify the IDE controller is enabled. Then check the cabling and jumpers on the IDE DVD drive. |
Watch the POST screens at start up to verify the BIOS is properly configuring all your drives by model.
No, your SATA DVD drive can't block the IDE DVD drive.
If you are attempting to boot from a disk in the IDE DVD drive you must have the boot order set with THAT drive in the boot order and before the hard drive/s.