I work for Netlfix so I will answer.....best I can at least.
Its basically all on our end, and oddly enough it doesnt effect everyone. Just certain people. Usually when this happens, it because our file paths are off after updating new content. Usually we resolve it soon. And this just doesnt happen to the 360, our devices like Roku alos have this problem, but not with all users....
If it isnt fixed by today for you all let me know, I'll pass along the info, even though I am pretty sure theyre already on top of it in the web department.
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