internet videos are a black screen

I just added a second screen to my desktop. After getting that working suddenly all internet videos are solid black screens. I hear the audio and see all the controls, but if I fiddle with the video it freezes on me and a pop up saying shockwave flash is busy or non responsive, the audio also stops at that point. same result weather i use internet explorer or Firefox. Have uninstalled and downloaded/installed flash player a couple times. rebooted my computer nothing changes. how can i fix this?