Why can't YouTube video clips be played back in full-screen mode on the VAIO computer?

YouTube video clips cannot be played back in full-screen mode on the VAIO computer, though it is fine in normal size mode.
For VAIO computer that comes with ATI graphics:
A black and gray screen is displayed.

For VAIO computer that comes with Intel graphics:
A black full-screen is displayed.

To resolve this symptom, please update to the latest Adobe Flash Player.
Adobe Flash Player Installation:
https://www.adobe.com/shockwave/download/index.cgi?P1_Prod_Version=ShockwaveFlash&P2_Platform=Win32&P3_Browser_Version=MSIE