This has been an ongoing issue since DAY 1 of my new AppleTV 2 box. Netflix blames Apple, Apple blames Netflix, and customers suffer as usual. I have totally stop using the Netflix feature from my AppleTV since it has not been reliable and have been using my Blu-ray Players built in Netflix which has been operating perfectly.
I do like my AppleTV for it's other features that have so far worked, except for the occasional pull the power plug to reset, (due to no off switch in the front) it has worked fine. I do not expect Apple to fix this issue anytime soon, and I do beleive it is an Apple issue and not a Netflix from the hours I have spent on it as well. From what I have seen if things go this far a long without a fix it is becuase Apple has shelved the issue. Similar to clearing old email cached addresses from the iPhone, an issue that has been shelved as well.
If you want a reliable Netflix look else where such as Smart TV's, PS3, or those that are built into DVD & Blu-ray players. For the most part those work with Netflix with no issues. If you want to continue to use your AppleTV for Netflix, then expect to pull the plug on it for a reboot often, and if that does not work then file a complaint or an RTA with Apple.
Our hands are tied with this issue that has been posted here and on previous threads that have mysteriously been closed.
Just my 2 cents from what I have seen with this issue.