hello peter
thank you so much for asking as i am quite ready to send my laptop back to where it once came 
well, as i understand it there is a bug with the AMD Graphics card
when i try to draw a shape, add a new layer, use the alt key to "cut" the line of the pen tool the canvas goes totally black and i cannot use the filters or the 3D tools. also, the bg area behind the canvas changes from dark grey to black to transparent
all of the above are reasons why i saved for 3 yrs to buy a new laptop w/a decent graphics card and it's just totally bum'n me out
if i understand correctly it's an issue between the AMD and Windows 8 ~ so as of now i am thinking i should either send it back or get rid of Win8 and install Win7 but actually now that i think of it i dunno if Win7 will correct the AMD issue or not but i think it would.
at first i thought the issues were Adobe related and not as i seem to have found
my laptop is a Satellite S875-S7376 the gpu is an AMD Radeon HD 7670M, the hard drive is 1TB, i7, and it has 8GB ram, 64bit, Windows 8
i went to AMD's website and if i understand correctly there is a "fix" that is helping somewhat but NOT for Toshiba notebooks, Sony and Panasonic and AMD is no longer releasing updates every month but only when they feel they have good enough reason to do so.
i've been unable to find an idea of when AMD thinks they'll have a fix for Toshiba and i've only got under 2 weeks to return this laptop
i tried to install something called the AMD Catalyst or maybe it's ATI Catalyst Mobility but was told it could not be installed due to incompatible hardware/software on my computer
i just wish i could get back to work and decide what would be the best thing for me to do
i seem to be making some folks upset b/c i keep trying to chase down an answer/solution. for instance i didn't realize that the problem i am having is called Flickering and so i had posted again about it at photoshop.com and was given a lashing about how i was already told this and that. 
i was also told that the solution is to just set Photoshop to Basic Draw Mode ... but that is my whole point as i don't want to have to use Ps in Basic mode as the entire idea of investing in a better computer was to be able to enjoy the bells and whistles
if you've got any ideas or you know of a solution or even if you've heard of one rolling on down the road i would greatly appreciate anything at all that you could share with me 
sorry if i ramble a bit much i'm just frustrated beyond the point of clarity
thanx again so much for your time & efforts!!