Awful 1st Experience: Netflix Streaming on Xbox 360

I had eagerly been awaiting yesterday’s Xbox 360 NXE (Next Xbox Experience) update to gain access to Netflix instant streaming to my 40” TV. I gave it my first try last night watching National Treasure 2 with my girlfriend. Everything started out smooth and I was impressed by the best non-HD quality video it had determined my connection could allow me, it was like watching a slightly more blurry DVD quality video (far from bad for streaming).
About 27 minutes in, just when I was convinced that Netflix streaming on 360 was the best thing since Netflix itself, the video stopped and screen came-up saying that my “internet connection had slowed” and it was adjusting the video quality to accommodate. After a progress bar finished loading the movie started again but the video quality had dropped dramatically so that it looked like a low quality YouTube video blown-up to fit my 40” TV. Needless to say I was far from happy. I checked all my router settings at this point and even reset it. Each time I restarted the movie where I left off (a great resume feature is built-in) the picture quality would be back to the good quality for 10 to 5 minutes before giving me the same message and reverting to low YouTube quality… Because at this point the movie was about half way finished I just let it play…
My ISP is Charter Cable and I have their 5Mbps plan. Apparently Charter is unable to provide me with a stable 5Mbps connection. If this keeps up I will no doubt be complaining to them very soon.