Windows 7 / Downloaded Flash Player 11 Now Not Working

i just downloaded flash player 11 on my computer with windows 7 operating system. after i restarted the computer, i began having problems with the playing of some online videos. some played fine, while others just left a solid black screen on the screen. when i clicked around on the solid black screen, and got the video to where it was "full screen", the video played fine. however, the video would not play unless it was on "full screen."

the smaller screen on the webpage would remain black and i couldn't see the video. it was very strange also, that i could hear the audio, but couldn't see any video. it is also very strange that not all the online videos did this. there doesn't seem to be any pattern as to whether or not the videos reacted this way. some c-span, Internet, etc. videos worked fine, while others didn't. prior to downloading flash player 11 i never had this problem.