For those interested on using PlayOn with Roku or PS3, or any other device.
I contacted PlayOn support and they strongly suggest a CPU with 500 Passmark score or more.
This website:
http://www.cpubenchmark.net/cpu_list.php provides CPU names with their corresponding passmark.
It looks like this is part of my problem, when using PlayOn I mean ...
I am in the process of test that with a faster CPU or buying a used computer instead. I will post my specs once the issue is fixed.