Could the removal of optical drive affect track pad's ability to work?

I removed my Optical Drive a year and a half go after I replaced my original hard drive with a SSD card. I put my HD in the optical drive's spot to increase the storage in my laptop. T hank you very much iFixit tutorials!!!!This was a great improvement!

However, in the last month my track pad began acting 'wonky' jumping all over the place to the point of uselessness. I took it to the Apple store and they said if I put the Optical Drive back in, they would replace the trackpad for $90. Once I put my original Optical Drive back in and removed my HD, my track pad went back to working just beautifully. Why would this be? If I have the Apple store replace the track pad, can I remove the Optical Drive again to put the HD back in it's place? Or is all this opening and moving items a bad idea? What should I do when I do this re replacement so that my track pad doesn't return to it's 'wonky', jumping around state again?

Thank you so much for any advice that will assist me!!!