Slight Movement - Immediate Lockup

I have a 13" 2009 MBP (2.53GHz C2D)

About a month ago I was toying around on boot camp, probably playing Sim City 3000 on Windows and thoroughly enjoying myself when POOF

System locks up

Thinking no big deal. I force a shutdown, wait about 15 seconds, and press the power button again. Instead of anything on the screen, I find myself terrified to the sound of 3 beeps.

So I research the problem, understand it is the RAM, so I open the bottom of the laptop, blow the dust out and jockey the RAM around (switched the slots) before I boot it back up to a successful boot.

However, ever since I have had nothing but problems with system freezes. Between closing the lid or just moving the system around, everything, including the mouse, locks up.

I recently upgraded the hard drive, thoroughly cleaned and again switched the RAM around before I installed a clean copy of Lion. I don't have Windows up and running yet on my new partition but I've slowly been building my new "system" and everything has been great.

Except here I sit in class to the system freezes and lock ups...yet again.

I suspect the RAM is the culprit, but I don't understand how any movement and/or the accelerometer could screw the RAM up.

Is there a correlation between the RAM and movement with system freezes? Is there any way to disable the accelerometer's effect on the HDD?

Any help or suggestions would greatly be appreciated

Thanks for your time

-
RS

 

Woah thank you so much for the detailed responses!

It started BEFORE I upgraded my HDD, and had regular lockups with the stock 250GB Fujitsu HDD after the sudden crash of my machine like I talk about in the initial post.

It is a 500GB Western Digital Scorpio I installed a month ago, and the lockups have been less frequent, but still happen from time to time.

I finally logged back in here and found these answers, and have just disabled the motion sensor through terminal. I will get back to you if that solves my problem!

Thank you for your responses and time.
RS

 

Still locking up after disabling the motion sensor.

I think I'm going to try reseating the RAM tonight or tomorrow and see how that works.

Would it be an issue with the RAM or the slot(s) themselves?

 

For the poor guy frantically searching the forums for an answer to this same problem, it was the RAM.

For anyone else who was following this, I tried both sticks of RAM in both RAM slots and found my system unresponsive to the bottom slot, only recognizing 2GB of RAM total instead of the two 2GB sticks, and when it did recognize any RAM in the second slot I encountered all of my freezing and kernel panics.

So here I sit on 2GB awaiting a 4GB single SODIMM from Amazon. However, this is only a temporary fix, and I'm not sure what to do.

In moving all of the RAM I used compressed air so I don't think any particles were causing the issue, and this issue began before I ever opened the MacBook.

So now what else can I do?