Air Boxs.

Hi , Is there anyone on here that can offer an explanation. I bought an Airbox last year ,i have Internet Speed of av. 8.0  iwhich i was told needed a steady 3.5 to ensure a good picture on my TV since then have regular problems with picture freezing. They now say that my PING readings are unstable and this can be causing problems. Telefonica Land line and ADSL and no problems with connection to the computer ,excellent,Telefonica spent hours checking my line and gave it a clean bill of health. So the question is why am i getting problems .If there is anyone who understands these Internet based Airboxs i would be very grateful for there advice ,also if anyone has had or has an Airboxspain please relate your experience  good or bad with it