I just found this thread today and read it entirely. I have a 5105-s701 that certainly has the same problems, but with a few peculiarities that might help us sort the problems into a few categories.
I only receive video artifacts/corruption/noise (basically something that shouldn't be there if the machine were functioning properly) at two distinct moments during the past three months:
1. at boot-up. when xp or linux is "starting-up" video garbage can be everywhere. remarkably, when i move the panel (screen) the video garbage seems to increase and move.
2. only one other time is video garbage viewable. when firefox cannot connect to the internet, a small white vertical line appears through the "cancel" button.
my solution thus far:
each time i receive video garbage at boot-up, i simply shut the machine off immediately turn it back on. for the first two months of my problem, every time at the second boot-up, the boot-up screen displayed correctly and the session continued with no visible problems (save number 2, which is constant). this past month, the problem has gotten worse. sometimes, i have to turn the machine 2-4 times before i get a clean boot-up screen, which insures me of a clean session (save number 2).
what this may imply:
i only boot-up in the mornings, and it's cold in pennsylvania. my problem doesn't seem to be heat related. in fact, the more warm my computer is, the less problems i have booting up. (for example, if i shut down after an hour or so, and immediately re-boot, i rarely have video garbage at boot-up unlike on a cold morning after the machine has been off for a night).
i'm not running at an extreme temperature (i keep it at roughly 45 C with Sensors Applet 1.5.2 (linux)). i'm not a gamer, basically use internet, office software, music.
it's common knowledge that these machines have a heat problem (it was told to me when i bought it), and that they were marketed as a desktop/video dream in a laptop case (read high temperature). so i'm not ruling out heat just yet.
but my question to some of the more experienced of this list (rich, etc.). what explains the problem when it's cold? wear and tear from previously hot sessions?
i have traveled with it a lot. maybe something's loose. i'm taking it to a laptop repair guy around here. 40 bucks for diagnostics. ladies and gents, this is my only recommendation: find a good local mechanic. these bestbuy/compusa service centers (and from several readings on this list also the toshiba mail-in service center) is over-priced and sometimes yields wrong service. i'll let you all know how the diagnostics go. btw-i'm printing out this thread and bringing him a copy.