Some of flashs is not shown while audio in these flashs is played normally. Some other flashs work well.
For example, flashs in http://helpx.adobe.com/flash-player.html works well, but those in http://www.adobe.com/software/flash/about/ is shown as white blanks.
OS: Windows 7 SP1 x64
Browser: Firefox 27.0.1
Flash Player: 12.0.0.44
I have tried reinstalling flash player, disabling hardware acceralation, and running firefox in safe mode but none of these methods helps. However, flash player for Internet Explorer on the same computer works well and display all flashs correctly.