Finally fixed my laptop/wifi. Hopefully some old toshiba owners find this thread if they have the issue with their laptop freezing/screen going multi-colored and pixellated.
I read all over the internet for over a month and found TONS of posts on various sites about this issue with the atheros wifi card causing these problems with peoples laptops. Everyone's fix suggestions was always to update the drivers, but this doesn't work because it's definitely a physical problem. I had found that when I would bang on the laptop it would unfreeze, clearly that has nothing to do with an outdated driver.
I tried a million different methods to make this work, but finally figured out a way(as ghetto as it is) to make the damn thing work. The card doesn't seat right in the slot, and I found that the card needed to be wedged up a little to make a solid connection. I cut a piece of speaker wire(probably like 10 or 12 gauge) about 1 1/2 inches long. Put in the card as usual, then wedge the wire underneath the card. Don't force it but shove it under enough so that it's snug and the card won't go back down. This helps keep the card in solid contact with the top terminals(where I think the problem is). Since this fix, I've moved the laptop hundreds of miles, in and out of my car and all through my house and it's worked perfectly for a month+.
Heres a quick picture of my fix (sorry, it's as ghetto as the fix
)
I hope someone with the problem finds this, because I've never seen a proper fix anywhere for it yet!