Dear all, I installed my stock (Apple) Hitachi 5400 RPM HDD in my MacBook Pro mid 2010 using an Optibay caddy. The installation went smoothly. My Bluetooth goes crazy when I transfer any large file between my HDD and SSD or read a large file from the HDD. I can barely move the mouse pointer on the display at times; if I'm typing something, one key would get locked and keep repeating itself. The interference occurs when the HDD is reading or writing at its peak (at blue arrow in image below). It almost feels like it's hogging up resources to preventing the mouse or trackpad from working smoothly. Could someone lend me a thought as to what I could do to fix this ? I've tried resetting the PRAM and reconnecting the module cables inside the notebook, making double sure everything is perfectly fitted. Many grateful thanks in advance.