I am new to Ubuntu and have installed the most recent copy of Ubuntu 64bit. I also have a relatively new NVidia video card, GeForce 210 1GB DDR3. I have downloaded the drivers for linux from NVidias web site, will this fix the problem and also I am not sure how to install them as well.
Have you gone to setting then restricted drivers this will install any driver you need.
For choppy playback install the flash-helper firefox plug-in it will sort your flash out for you.