Have Dual Boot MBP 13" Mid 2009 Unibody with Mountain Lion and Windows 7 Pro 64-bit. Recently bought an SSD drive thinking my original SATA drive had gone bad due to Windows 7 locking up and Mountain Lion causing database crashes in MS Outlook for Mac. Was expecting some performance increase from the SSD drive but still had same problems.
Determined I either had a bad Hard Drive Cable or worse, the I/O controller on the Mother board was bad.
Tried the least expensive route first.
Repair went terrific. Instructions online were spot-on not that it was a difficult fix to begin with. Noticed that the old cable had dimples in the plastic right near where it bends at 90 degrees to follow the contour of the Optical drive casing that the hard drive cable is fastened against.
I used to carry my MBP in sleep mode in a backpack and I suspect that the laptop was getting squeezed as I walked and the bottom cover was flexing enough to pinch the Hard Drive cable against the somewhat sharp corner of the optical drive casing. This contact probably caused some shorting as the plastic hard drive cable seemed to have dimples in it as if slightly melted.
For the new cable I added some double-sided foam tape to create a channel for the cable giving it additional spacing between the somewhat flexible bottom cover of the Unibody MacBook Pro and possibly pinching the hard drive cable onto the optical drive casing.
New Hard Drive Cable did the trick as the laptop is showing the performance benefits of the SSD Memory and both OS's are running super stable and rock-solid again!