Thanks for posting in the forums! I'm sorry to hear you are experiencing this issue. I understand the computer this happens on performs better than the computer this does not happen on. However, if it is only happening on one specific device and not on any other, it is an issue with the device.
It may be an issue with the SlingPlayer plug-in. Have you tried other browsers to see if this issue persists? Also, what operating system is your computer currently running on?
Have a great day!
The Sling Moderation Team