Scott,
Something doesn't add up here.
You mentioned that you never turn your computer off and that every time that you've had to for any length of time, it spits the dummy.
What I can't make out is why after an arbitrary power down period, the computer refuses to boot up again?.
I was thinking that it could be something temperature related on the motherboard itself, that has cooled down and is no longer making contact upon re-starting, the likes of a bad solder joint on a SMT device or what-not.
Just my $0.02 worth.
