The AppleTV 2nd Gen definitely has buffering issues with Netflix, and the problem is not with Netflix or the network.
1. I have used 2 other streaming devices (Sony PS3 and WDTV Live Plus) on my network (hardwired 100BASET) and Verizon FIOS (allegedly 35Mbps download speed) ISP connection with no Netflix issues.
2. When I stream a movie stored on my iTunes Server through the AppleTV, everything is great. The AppleTV streaming progress bar shown at the bottom of my TV screen indicates that the movie is streamed to the AppleTV well ahead of the current playback point. For example, the progress bar shows that an hour long video clip is completely downloaded to the AppleTV before I have watched the first minute of the video.
3. In Netflix mode, the streaming progress never gets passed the current playback point. It doesn't seem like the AppleTV is buffering anything. In this case, any network delay at all will cause a playback issue.
Hope this description helps Apple solve this problem.....