NIS 2013 Corrupts Streamed Web Music after 17-20 Minutes

This problem has plagued me for quite a while and at first i didnt suspect  NIS 2013 ( all versions do this)

But when i play musc from Youtube ... an hour long session etc ,  after 17 - 20 minutes the sound breaks up as if NIS is performing some background task ,  i have set it  in Norton Tasks to   Task delay 20 minutes . Idle time - OFF .  Idle time out - 30 min . 

And it STILL does it !!

However  if i disable Norton altogether the music plays flawlessly for the entire hour .

What else can i turn off ,  silent mode has no effect . It has to be off completely at present .

Thanks.

 

Windows 7 64bit .

NIS 2013  20.4.0.40