I'm having what appears to be the same issue, when watching TV through media centre, or watching a film using with VLC or Media Player the screen goes white or light blue (Not the blue screen of death). Its a White screen when connected using a VGA cable, and a light Blue screen when using a HDMI cable.
It can happen a few times in a day, or go a week without happening, its very sporadic, and has no noticable pattern.
Another symptom of this is it does this when plugged in via VGA or HMDI, but when it does this through HDMI there is a buzzing sound that comes through the audio that never stops (Well untill I pull the power cable out).
I too have ran windows updates, and gone to the Acer website to download the latest updates and it made no difference.
There is one other thing that I have noticed, I'm in England and we watch TV shows using the BBC iPlayer, and thats uses Adobe Air, and thats got issues on my PC now, it wont save any settings locally e.g. Where to save programs so it wont let me download TV shows to my PC, I now have to stream them.
I'm going to try unistalling Flash and Air and see if re-installing them fixes the issue
Any help appreciated