This Really Jiggles My Biscuit. Currently Running My 4th Apple Hardware Test, With No Luck On Finding Any Problems, Except, Running The Extended Test, The Bar Makes It Just Under Halfway, Ending On 'Testing Main Logic Board', At Which Point The Fans Stop Whirring, The Install Disc Stops Spinning And It Just Says Test Complete, No Problems Found.
It All Started With The Question Folder, So I Checked These Forums And Quickly Discovered It May Be A Hard Drive Issue. I'm Just Out Of Warranty, And I Only Have PC World's PC Protection Plan, Not AppleCare, And Knowing Full Well How Cr*p The PC Performance Handle Mac Issues, I Decided To Bypass The Whole Shebang And Just Buy A New Hard Drive. That's Not Here Yet, I'll Try And Post Back When It Gets Here, But Until Then I've Tried One Or Two Things. I Took Out The Hard Drive Myself (
http://www.youtube.com/watch?v=uuyi-NWLLz4 Check This Video For How To Do It If You Don't Know, You'll Need Torx 8 And Phillips Screwdrivers) And Plugged It Back Into The Macbook Through USB, And Ran The Disk Utility App From The Install Disk. When The Hard Drive Was In The 'Book It Didn't Show Up In The Slightest On DU, And I Just Had The Flashing Question Folder. When I Plugged The Hard Drive In Through USB I Got A Circle Symbol With A Line Through It, and DU Then Showed My Hard Drive, But Said It Did Not Need Repairing. These Results Have Made Me Worry That The Problem Is The Logic Board, Not Hard Drive, Which I Can Easily Replace Myself.
Just Thought I'd Post My Two Cents On Here, You Never Know, I Might Have Given A Little Nugget Of Usefulness To Someone =D