Hi pals..
This is actually a simple problem and most of you would be knowing the solution too. Still for all newbie's like me this post would help you to some extent.
Recently I encountered a problem while trying to play videos posted on my facebook wall in my favourite google chrome browser (version 5.0.375.125).None of the video buttons worked once I started to play the video.It was so uncomfortable as I could neither control the volume nor I could pause it. So when I googled up, I found that there was a temporary and very easy solution for this. The trick is that you need to adjust the zoom control in the browser and come back to the normal mode.
One can adjust the zoom control settings to NORMAL MODE by just
PRESSING ctrl + 0
OR
you can click on the "control the current page" icon on top-right corner of your broswer and select normal mode in zoom option.
So after you come back to normal mode, You will not find difficulty in having control over the video buttons on facebook.
one disadvantage of this is that the font size decreases to some extent,but that shouldn't be a problem playing videos isnt it !! You can always zoom-in in case you need a larger font size!!