Adobe Flash Player 10.1’s HD hardware acceleration feature can cause a green-screen error when attempting to play online high-definition (and even some standard-definition) video, such as on Youtube and Vimeo. It appears that it conflicts with the Sideport memory found on some motherboard with integrated ATI graphics, such as the Asus M4A785TD-V EVO with its ATI HD 4200 chip.
There are two workarounds, neither ideal. The simplest is to right-click the video, choose “Settings”, and uncheck the “Enable hardware acceleration box” found under the “Display” tab. This, of course, means that the whole point of the Flash 10.1 update—HD hardware acceleration—is disabled.
The other option, and in my mind the preferable one, is to disable Sideport memory in the BIOS. In the AMI BIOS for the above-mentioned Asus board, the relevant options are found under Advanced → Chipset → Internal Graphics → Internal Graphics Mode → UMA. Of course, this ‘solution’ is also irritating: the Sideport memory then becomes another feature paid-for-but-disused.
The best option, is, of course, dependent on Adobe/ATI (whether the problem lies with Flash or with the ATI drivers isn’t clear) updating their software to fix the clash. Here’s hoping they actually do fix it, otherwise the users—as so often happens—will be left feeling shortchanged.