The only times I have had trouble with ultraflix was when my service was not up to par. Even though I have 300 megabits per second internet service it does not mean I always get that. If you have problems you need to go to fast.com and do a speed check and see what you're getting. I was only getting about 1 megabit per second when my problems occurred. The internet service providers can't actually always keep your speed at what they promise.