What do Minecraft, Skype, and Firefox have in common?

[usaipad]

Because they all crash my computer (among other things that I currently do not have access to (namely certain Steam games, especially big ones like TF2 and L4D2)) and I'm apparently stumping the people at the Apple Store's Genius Bar with it. They've replaced both my hard-drive AND my Logic Board, and it still happens.
It even happens in Windows 7 OS, once I got a copy and dual-booted it onto my computer, meaning it has to be a hardware issue or a software issue that my personal hardware just reacts nastily to and that occurs on both Windows AND Mac OSes.

The two main things it does are that the screen blacks out as if it lost power, and any audio in the background starts looping in a very short loop, becoming totally unresponsive until I force my MacBook to shut down.

I'm posting this here mainly because I doubt that Apple can figure out what the problem is even though I am going back today. AppleCare warranty has been more than worth it at this point, I figure I should keep making use of it.

This is extremely annoying because I mainly used my computer for gaming and Skype, and now I can't do either.

[Xram]

Your problem is not Minecraft, Skype, and Firefox your problem is that pish they call apple. I know what your going to say Apple (Steve jobs ) gave the world the mouse yes they did then the got rid of the *****. Why would you want anything that runs on an apple system??? Apple have got to be the best for innovation on the planet only problem they have is there OS windows does have its issues ill admit but its generally user friendly and cheap (unlike apple no wonder it keeps the doc away he cant afford the system) linux free all day very few issues with the system hey they may look at you and call you a geek for using linux (a system i dont use very often but a great system all the same ) does what it says on the tin and wont charge you for going over your limit.