i have this problem too
since many many many people have the problem tells me it is a design flaw in adobe flash when facebook gets involved
install an older release, 10.3. There have been many conflicts with newer releases of Flash and various video cards. You might try updating video drivers if any are available.
do not know about origional poster but there is no updated video drivers for people running windows 8
also if you try and use a older version of flash facebook games just tell you to update flash
seems we are back to adobe must fix the conflict