There are a number of different reasons you may be running into that are causing video playback issues. Internet connection, browser bandwidth, plug-ins/extensions, or an out of date Flash Player are all factors that could be affecting video playback. There are a few things you can do to optimize your video playback experience.
1. Check your browser: try playing the video on an alternate internet browser (e.g. Google Chrome, Mozilla Firefox, Internet Explorer Safari), and see if the experience is improved.
2. Make sure Flash is up to date. If you're not sure if you have the most up to date version, you can check here. To download the most recent version of Flash, click here.
3. Clear cache and cookies.If you need instructions to do so, click here.
4. Change the resolution on the video.