I guess nobody else has a solution for you. I have a temp solution, until it is fixed.
You can turn offhardware acceleration in VLC and flash ( for youtube) That should help a bit.
If you dont know how to do that.
While on youtube right click on the video
Go to "Settings..."
Click on the tab with the monitor on it and uncheck "Enable hardware acceleration"
I do believe that VLC has hardware acceleration but i cant find it in the advanced settings ATM, but im sure its in there somewhere.
Hope this helps