Welcome to Apple Support Communities.
1. It IS possible to press too hard or wiggle too much and cause damage to the 'memory slots' inside the computer. Apple memory slides 'straight-in', parallel to the outer case surface, (and not at an angle, then snapping into place, as many PC memory cards do). If a RAM module was forced in 'backwards', damage might have happened, and there is no easy fix, because the connectors inside are soldered to system board.
2a. It is possible that the replacement memory, even memory purchased direct from Crucial, is not the correct spec for your computer.
2b. It is possible that the replacement memory is defective.
However... IF either of these cases occurred, I would expect that replacing the original memory would restore 'normal' operation, and that obviously did not happen.
3. Even though not indicated (by the Apple info in the following link), in one instance, I needed to reset the NVRAM/PRAM (multiple times in a row, actually) for a new configuration of compatible RAM to be properly recognized. http://support.apple.com/kb/HT1379
4. An SMC reset, also not indicated as likely to help your problem, would not hurt.
http://support.apple.com/kb/HT3964
5. It is possible that you slightly dislodged the hard disk drive from it's connector. The hard drive slides out to the right/in to the left, when your battery compartment is open and the 'L'shaped metal cover is removed. And too much force could also damage the hard drive connector.
