and the SATA DVD Writer is also set as a Master
No.
SATA devices do not use Master, Slave or Cable Select. Those are only for IDE devices. This is because you can connect two devices to each IDE cable and the IDE interface controller must be able to determine which is which. SATA only supports one device per cable so the SATA controller does not need to sort that out. In the vast majority of cases, you never have to mess with jumpers on SATA drives - especially those made in recent years.
With IDE devices, you have a two main options with strict rules:
Option 1 - Cable Select (CS). Both drives (or one if only one drive is used) will be set (by jumper) to CS. The IDE HD controller will determine which is Master (MA) and, if two drives, which is Slave (SL) by the drive's location on the cable. On the cable, opposite the motherboard connection is the Master and the one in the middle is the Slave. If only one drive is used, connect it to the Master cable connection. If two drives, determine which one you want as Master and connect it to the end connector. I generally put hard drives as the Master and optical drives as the Slave.
Option 2 - Master and Slave (MA/SL). With one drive, it will be set to MA. With two drives, one will be set to MA, the other to SL.
Rule 1. Do not mix CS and MA/SL on the same cable.
Rule 2. When looking at an IDE cable, note the middle connection is not exactly in the center, but closer to one end - the Slave is always closer to the Master.
Rule 3. There will never be a Slave drive by itself. If only one drive, it must be a Master with the jumper set to MA or CS and it must be connected to the Master (end) connection.
If mixing SATA and IDE devices in the same computer, it may be necessary to adjust the Boot Order settings in the BIOS Setup Menu to make sure the system sees the boot drive first.