Same exact issues with Samsung TV and Netflix!! So annoying, especially since it worked fine for so long! The past couple months we have been getting "Netflix cannot play the title at this time message" which was annoying in and of itself. But now it prompts us to log in every time, too! I'm glad we're not the only ones. I thought it was a Netflix issue, and they just kept telling me to contact my ISP and have our connection reset. I knew that wasn't the issue b/c we can stream just fine on the Roku and our computers.
Just a little FYI... I was searching on another message board about this issue, and one 'solution' to the problem was to go into the TV's network settings and change the DNS settings to 'Manual' and the address to 8.8.8.8. Doing so seems to have cleared up the 'Netflix cannot play the title at this time' message, at the moment anyways. But we are still having to log in. :( Will be watching for updates, thanks for posting!
