Hey there!
Sorry to hear about the consistent issues. If the hard drive works well in other instances, the issue may be as simple as a poor SATA cable. The hard bend in the cable leads to high failure rate while removing the optical drive or replacing it with the new Dual drive. If you still have your original optical drive, I'd try putting it back in and seeing if you can get it to read. If your laptop is having issues with that, you probably have a cable issue. It's a fairly cheap part at $20, and could be the answer to your problems. Other than that, I'd try cleaning the connection on your board and making sure that your current SATA cable doesn't seem overly bent or worn.
Replacement cable: [product|IF161-040-2]
Best of luck in your future repairs!